I second the problems with the trigger reset on the LCR. I took a look at them and they were a total no-go for me as it was relatively easy to short-stroke it in rapid fire.

I own two 642's and a 442 that I use as a training gun. Both are good choices, but I would probably recommend the 642 due to it being stainless steel and more rust resistant. I've had a few spots of rust on the barrel and cylinder of the 442. The 642's silver finish on the aluminum frame is probably a little less durable compared to the black on the 442, but it's really only a cosmetic issue. If the finish on mine gets too bad, I'll probably just get them refinished in black. Too bad S&W doesn't make black 642's.