Lets hear what you think about each one

Fluorescent :

Triphosphor - proper lamp to use in most applications. Good light quality, highly efficiet, good selection of colors

Halophosphor - good enough for few borderline applications (mostly non often used lights), allthough the lower CRI provides for somewhat more relaxing light in some applications, so it might be suitable for e.g. full-night, low level light



LED tube light :

Is not a lamp of its own type, it is a fake "better Fluorescent lamp" and intended for sale & use as such by its manufacturer

Saving energy by providig half the light for half the power consumption (compared to the Triphosphor Fluoresent). Assummed (wrongfully) to equal a Fluorescent, based on the assumption that only the light emitted from a Fluorescent lamp downwards is useful. In reality the LED tube provides less light into the room

Since there is no (or reduced) upwards light, the visible background behind the tube (ceiling, ...) is darker than with Fluorescent lamp. The lamp in front of a dark ceiling = appearance of higher glare, ceiling may appear sooted like after a fire

Poorer light quality than the Fluorescent due to narrow and inequally filled spectrum, regardless of CRI and light color

Not a huge LED fan here. Hate 'em as Christmas lights or incan replacements. But, I don't mind replacing most types of fluorescent with LED. Main reason for me is that typically fluorescent lamps, until recently, have been low CRI. And they dislike cold conditions, and they are usually found mated to the wrong type of ballast.

I have replaced all of our general purpose fluorescent with T8 retrofits that are direct-wired, another must have for me. Don't be lazy, disconnect the ballast! All of my T8 LEDs are 4000K and are actually higher lumens than the lamps they replaced, combined with their 180deg light output makes them seem much brighter.

I also don't mind replacing CFLs with GOOD LED bulbs. I have never liked CFLs anyway, the LEDs are an improvement to me, I know many will disagree!

A huge no-no in my home is replacing incan with LED. Here in my area we pay very low kw/hr so there is no "need" to get rid of incans. We wouldn't notice it on our utility bill anyways.

To be sure, I do collect fluorescent lamps and I am a stickler about driving them with the correct gear, I will match ballasts to lamps to ensure longevity and performance for my collection. But for GP I really do prefer LED T8 retrofits.

@takemorepills. Thats all well and good here, the T8 LED tubes are great for places where its colder and gas based lighting would suffer as well as a shop environment where bright light is needed.

I have deployed 4 LED tubes in the house late in 2016 or so but they are the ones that use the existing T8 ballast. I honestly prefer the ballast LED tubes because I view it as safer than direct wire
since there is no need to mess with the electrical and it keeps the fixture UL certified.

Most important to me, It eliminates the possibility of the scenario where the LED tube goes EOL and if I'm not around to change it and someone else assumes it is just a fluorescent and takes it upon themselves to replace it with a gas tube not knowing better, they risk a dangerous explosion from the tube being direct on mains.

I agree with you on the CFLs, I never liked them either and my interest in them only died off for good after seeing some attempt to catch fire, so instead I use the LED filament lamps which are much more better than CFL, they are brighter, run cooler, can be used in -40 c weather full brightness and best of all they look and feel just like a normal classic bulb. The only LED I approve of! Unfortunately utility cost is fairly high in the Province of Ontario, thanks to Hydro One being corrupt.

Me too, I must drive the fluorescent tubes on the right gear for them, though sometimes I like to experiment! 

I have deployed 4 LED tubes in the house late in 2016 or so but they are the ones that use the existing T8 ballast. I honestly prefer the ballast LED tubes because I view it as safer than direct wire
since there is no need to mess with the electrical and it keeps the fixture UL certified.

Most important to me, It eliminates the possibility of the scenario where the LED tube goes EOL and if I'm not around to change it and someone else assumes it is just a fluorescent and takes it upon themselves to replace it with a gas tube not knowing better, they risk a dangerous explosion from the tube being direct on mains.

Do you know for a fact that removing a ballast voids the UL certification? Not trying to blindly argue, I do work with UL Listed equipment at my work, we are allowed to do whatever we want to the equipment configuration within the enclosure, but once we go above a certain voltage, modify the enclosure (as in, drill a hole in a spot not marked for an opening) or use it outside of its rated environment, the UL Certification will be voided. I highly doubt bypassing a ballast would void a UL rating, especially if you follow my 2nd point:
I only use the retrofit lamps that have AC L on one end, and AC N on the other end. I do not like to use the T8 retrofits that have AC L and AC N in the one tombstone. First reason is there is a risk of putting in a fluorescent lamp and burning its cathode. Second reason is there is a general risk of shorting during relamping. Third reason is if you try and install a T8 retrofit with AC L on one end and AC N on the other end, the tombstone wired with both AC L and AC N in it will definitely be shorted out. Going vice-versa, there wouldn't be a problem, just a dark lamp.
Because slimline retrofits require AC L at one end and AC N at the other and, and this is just a safer approach, I don't see why the industry hasn't standardized this configuration. I have done quite a few 4' T8 retrofits where both styles of AC connection are used.

I looked into it more after posting and apparently it will remain UL certified as long as the retrofit kit is UL certified, it will keep it intact for the fixture. So you should be good there after all. Now I'm not an electrical pro so do not take my word for it, I try to understand as much as possible but I may not be correct always.

Now adding holes into fixtures and such where they weren't designed violates UL ? Looks like some of us on the site are guilty of that including me! where we either mod fixtures or build them from scratch and most members do a damn good job too!

I still don't feel comfortable having mains connected directly to the sockets, its just me though, because what would happen if someone put a fluorescent back into it, even if N and L were at opposite ends ? For me using LED tubes designed for the ballast allows for quick swapping back to fluorescent. Its more for the brightness than to save energy. The fixtures are using about the same wattage as they did with 25w F32T8 lamps but have more brightness than a 32w T8.

At the end of the day as long as your comfortable and happy with your setup that is all that matters! 

I looked into it more after posting and apparently it will remain UL certified as long as the retrofit kit is UL certified, it will keep it intact for the fixture. So you should be good there after all. Now I'm not an electrical pro so do not take my word for it, I try to understand as much as possible but I may not be correct always.

Now adding holes into fixtures and such where they weren't designed violates UL ? Looks like some of us on the site are guilty of that including me! where we either mod fixtures or build them from scratch and most members do a (...) good job too!

I still don't feel comfortable having mains connected directly to the sockets, its just me though, because what would happen if someone put a fluorescent back into it, even if N and L were at opposite ends ? For me using LED tubes designed for the ballast allows for quick swapping back to fluorescent. Its more for the brightness than to save energy. The fixtures are using about the same wattage as they did with 25w F32T8 lamps but have more brightness than a 32w T8.

At the end of the day as long as your comfortable and happy with your setup that is all that matters!  

UL will void certification for a fixture/device due to mechanical modification because they can't be sure you haven't provided for continued ground protection (which is one of the major factors for UL certification: an enclosure that protects the user, i.e. proper grounding or isolation, you may be violating that by drilling holes or re-working metal). UL will also void certification because a modification/drilled hole violates the environmental resistance, such as drilling holes in a 4R box will de-rate the box.
UL looks at it like this: 120v goes into this "thing" and this "thing" has to be engineered to provide a reasonable amount of protection to a user. Grounding, isolation, touch safe, etc. Whatever happens inside the device is usually going to be contained by the engineering criteria of the aforementioned attributes. For example, a careless electrician leaves an exposed wire after a ballast swap...UL doesn't certify that a ballast swap will be done correctly, UL certifies that the fixture will protect the end user, either through grounding and/or isolation. I am just talking about one "thing" UL cares about, they have additional criteria to evaluate that doesn't add to this particular conversation.

Also, voltage is at the tombstones even with a ballast installed, and installing a fluorescent lamp on an opposite end fed ballast bypass won't damage the fluorescent lamp, at least not in the USA.

That all said, it depends on what you are comfortable doing. I can see why you prefer ballast-compatible retrofits. But, me personally, I don't mind cracking open a fixture and re-wiring it. easy-peasy. I will leave the ballast in the fixture with enough wire to re-connect if I change my mind. I just don't like to leave the ballast in the circuit when it is not needed.

I wouldn't worry about violating UL in our hobby. As long as you take care to keep the fixture safe, you can do whatever you want. Keep your fixtures grounded and wires isolated and you'll be good, modify away!