I really like the way the high speed Cummins performs, and would consider a 1992 1680 if it's in excellent condition. The 1688's are also great machines, but hard to find. I think most of their owners are keeping them instead of trading. So we ended up going with a low houred 2188 a couple years ago because we could find one for the same $ as older machines. It's a 1996 model and has all the updates done on it. I would have preferred to have the '97 model with the heavier frame, but '96's are probably ok unless you want to run duals. I would avoid the '95's. As for 2388's, I like the 1999 the best. There are always a ton of '98's for sale, and I think I would avoid them for that fact. I think the '99 is the last year of the rear mounted rotary screen for the engine air intake. I never hear anything good about the new style, but haven't heard anything bad for a while either.