I'm old enough that the most recent gun I purchased was a revolver. Got a bunch of new-fangled stuff like Glocks and SIG's that I generally carry though.
When I took my carry class many years ago, I did it with a blued, 2 1/2" Model 19. I'd happily carry that one today, however, my daughter claimed it as hers when she was about 12, then picked out a pair of ivory stocks for it. Since then, it has been a safe-queen, waiting on her to turn 21. It will be part of her birthday present from Daddy, the other half is her carry permit.
As for the difference between the 19/66 and a 586/686, there is more than the 1/4 pound weight to make a decision on. I have a Performance Center L-Comp which is basically a tuned 586+ with a 3" barrel. I can detect the additional weight. I also notice that using the same holster (both have Don Hume belt slides) the L-frame is just enough bigger that the corner of the rear sight scrapes the inside of my arm as I walk. It is also a bit harder to conceal if you care about not printing. I live in Tennessee, own my business, and really don't care if I print.
If I were not on the way to practice for an upcoming match, this thread would make me carry a revolver today. You really can't go wrong with a quality wheelgun.