What makes one better than the other? I hear people always saying that the leaded version is better, but honestly I use both and Don't really notice much of a difference...

They have different temperature behavior and different flow/stick to properties. When doing manual work, especially when it is not on very tiny parts, you instinctively do what it feels like the material needs, whether it is to add flux, crank up the heat and so on. So you might indeed not notice too much of a difference. You will mostly notice difference when soldering big parts that sink the heat significantly. When doing automatic work, the Lead free solder makes a challenge as it needs more precise control over parameters of the process and is less forgiving than leaded

Also, in relation to the electronics being soldered, the Lead free soldered joints are more fragile. This means for example, that something soldered with Lead free solder can tolerate less thermal expansion/contraction cycling (both in amplitude and in number of cycles) before it breaks. So for example, if a heatsink of specific size was sufficient to cool down a GPU soldered with leaded solder, the same heatsink is inadequate for cooling the same GPU once it is soldered with Lead free. The GPU does not heat any more than it used to, but the amplitude (the difference between the coldest and hottest temperatures the joint cycles inbetween) is too high

For me it has to be  leaded solder every time. I've tried working with the lead free stuff and it was just horrible. Used in a properly ventilated space the proper leaded solder is perfectly safe. I refuse to be told what I can and cannot use by the 'nanny' state. 

For me it has to be  leaded solder every time. I've tried working with the lead free stuff and it was just horrible. Used in a properly ventilated space the proper leaded solder is perfectly safe. I refuse to be told what I can and cannot use by the 'nanny' state. 

Absolutely. Lead-free solder needs a higher temperature on the iron and if you're working on a very small and crowded PCB then you can ruin the tracks and totally b****r the whole thing 

Lead solder for me. I've heard of stress cracks and cold joints being common in lead-free solder causing electrical issues.

The lead free solder is more difficult to master. The problem is, it is not an eutectic alloy, so instead of just a single melting point it exhibits rather wide temperature range where it is partly solid and partly liqid and when is extremely "easy" to form cracks that will break later.

On the other hand to work safely with leaded solder you ned not only the ventilation, but as well protection gloves (mainly important when you do so every day for a long time - the led tends to get slowly absorbed via skin; not problem for a occassional exposure, but it is a problem when handling it 40 hors a week)
And theproper ventilation you need for both, maybe even more important for the lead free (due to the higher temperatures involved), as the culprit is there not the lead, but the decomposing organic matter in the fluxes and adjacent heat exposed plastic materials.

Lead only for me.

The industry really struggled with RoHS initially.

Lead-free gets "cold-joints" very easily, cracked fillets, and a big one is "tin whiskers".

You can re-work lead-free with leaded, it is what I do to restore early 2000's RoHS gear.

For me it has to be  leaded solder every time.

Same for me as well.

Here is my take on this, what the posters are saying is true, so what I would do is learn to use lead free solder it's not that bad and then you will find leaded solder to be easier to use and you will do a much nicer job as well, it's like learning to weld I've seen lots of people that can do a good job with a MIG or a TIG because that is what they learned on, but they suck with a stick, but the ones who learned with a stick and are good at it, excel with a MIG or a TIG welder. 

Also if you have close pcb tracks while this might sound totally off the wall, try using a halogen automotive light to solder with like the H4 bulb (any type with a reflector behind the filament will work) you can place aluminum foil over the parts you don't want heated and use the infrared heat from the bulb to heat the parts you do, large PCB manufactures use infrared heating on there boards, just practice on some older broken boards first to get a feel for it, and as an added bonus this will also help you see what your working on, so you might want to wear sunglasses or darkened safety glasses, and if you pre-wet (solder cover) the leads you just place the part and heat it while holding it down so other then the odd touch up you don't need to play with solder while your holding the light and the part down, which sucks unless you have a third hand to help you..

Here is my take on this, what the posters are saying is true, so what I would do is learn to use lead free solder it's not that bad and then you will find leaded solder to be easier to use and you will do a much nicer job as well, it's like learning to weld I've seen lots of people that can do a good job with a MIG or a TIG because that is what they learned on, but they suck with a stick, but the ones who learned with a stick and are good at it, excel with a MIG or a TIG welder. 

Also if you have close pcb tracks while this might sound totally off the wall, try using a halogen automotive light to solder with like the H4 bulb (any type with a reflector behind the filament will work) you can place aluminum foil over the parts you don't want heated and use the infrared heat from the bulb to heat the parts you do, large PCB manufactures use infrared heating on there boards, just practice on some older broken boards first to get a feel for it, and as an added bonus this will also help you see what your working on, so you might want to wear sunglasses or darkened safety glasses, and if you pre-wet (solder cover) the leads you just place the part and heat it while holding it down so other then the odd touch up you don't need to play with solder while your holding the light and the part down, which sucks unless you have a third hand to help you..

That sounds like way too much hard work, I'll just stick with my nice leaded solder and take adequate precautions thank you.!!

That sounds like way too much hard work, I'll just stick with my nice leaded solder and take adequate precautions thank you.!!

I though that to but if you ever have to work with a BGA (ball grid array) chip the rework stations are huge money and for a quick trip to the garage for a bulb and an old xbox power supply the cost was next to free and it worked pretty slick..

I though that to but if you ever have to work with a BGA (ball grid array) chip the rework stations are huge money and for a quick trip to the garage for a bulb and an old xbox power supply the cost was next to free and it worked pretty slick..

I've actually used an electric stove top for SMD rework