I've got a 642, and its a sentimental favorite. It has a very smooth trigger.
I keep it in the garage, in a tool cabinet drawer, to help me protect the house (when I have the garage door open and am working there) and when I need a grab-and-go gun for my pocket on a quick trip out.
I've also got a 442 Pro - and I like the moonclip feature. It allows me to carry a second 5 rounds in a rapidly re-loadable format, and is more likely to be carried in a Simply Rugged pancake.
Both are excellent revolvers. I don't think you could have gone wrong with either one. The differences are meaningful but not game changers, and you can easily adapt to the one you bought, the 642. (Who knows, you might get a 442 someday, or a 639, or a 640, or...).