I agree with all the guys here. I have 2 GP30's, a GP38-2, and an SD9 and ALL of them run GREAT! I have on the other hand had SOME problems with them at one time or another. Normally, its either cracked gears, some wire that has come loose (after I took the shell off) or other minor fixes, but most of which are to be expected with ANY locomotive. As far as them looking the best, I DEFINANTLY agree! They run smoother, pull harder, and actually IMHO have nicer details than any of their competitors. The only drawbacks is, as mentioned above, the ridiculously high prices these days, the cracked gear problem, plastic grabirons (as opposed to metal ones that are much better looking and of course more durable) and of course, it seems that there is not that much of a lineup and there are not alot of different locos to choose from! Alot of their old models are not available anymore....
This goes out to everyone as a FWIW: When I recently bought a B&O GP30 from Ebay and received it in pieces, I contacted Walthers. Although the service was VERY friendly and considerate, they were asking $60 for a replacement shell! I've checked everywhere and they are impossible to find!
The bottom line, P2K, strong runner, looks great, hard to find replacement parts and very expensive when you do!
-Rich