From my own experience, as far as MV lamps go, I would say the best were Westinghouse Lifeguards and the worst are the US made Philips MV made in the mid 90's up until they switched to imports in the U.S.

Somewhere around 1995(?), Philips redesigned the tried and proven electrodes designed by Westinghouse for their Lifeguards and made smaller. The result is a lamp that blackens perhaps faster than any other lamp I've seen. One example, I replaced several 250w US made Philips MV that were dated 2004 and this was in late 2006. Only 2 years old! These lamps were literally dimmer than a 23w CFL. The new lamps I installed were Chinese made Philips that after two years are still a respectable brightness. I have seen this in other instances where Philips 100w, 175w, and 400w lamps dimmed quickly as well.

The second best vintage MV lamps seem to be Sylvania. They have the second biggest electrodes and from the older high hour lamps I've seen, they seem to hold up very well. In fact, from all the different lamps I've seen, Sylvania seem to be the only ones to keep the same arcube design the whole span of their US made lamps from the 60's until the 2000's when they switched to imports. Ge redesigned theirs in 1980(?) and of course, Philips gradually changed Westinghouse after they bought them out.

For the U.S. made lamps, historically, GE and Norelco have always had the smallest electrodes. GE seems to have a mixed track record, as I've had GE's remain bright for ten years until they fail and others dim terribly. Norelco (Owned by Philips) were the worst from what I have heard.

I'd like to hear input from others on this topic. 

This is funny, because I was doing experiment and doing something with 2 of my Sylvania lamps..

When I receive old used MV lamps, usually its the Westy that will often guarantee work! mostly 175 watt and 100 watters....Most of the Westy lamps I get are from the 70s....and some from 60s still glowing nicely....dim but nice glow...70s ones tend to still be bright but 80s are much brighter....I have noticed 100 watt Westys tend to stay bright longer than 175 watt but 175 watt seems to last longer...

Now about Sylvania....often I get them usually some works and others don't...and they usually came from the 80s. I have gotten a few from early 70s but they are already very dim....now for those that stopped working...I have noticed Sylvania's EOL tends to be when mercury or starting probe gets "crossed" seems to be common on the Sylvania lamps when they are old and worn and dies.....

I got one back to life, but the other, no luck!

I would have to differ concerning the last of the US made Philips lamps.  I have several in the 175 and 400 watt range and they tend to do nicely.

Don you're pretty much right on! Although I'd like to add that the Sylvania Banner merc lamps of the late 50s/early 60s had longer, thinner arc tubes similar to the Westys.

I've seen many mercs fail quickly also. The 400w mercs on the LA freeways only last about 1-3 years, literally. Caltrans uses Philips lamps, so go figure.