I've looked long and hard at that S & W 642, haven't bought one so far but it may happen yet, it would make a great summer gun. I do nearly all of my shooting DA, so the cockable hammer doesn't really affect me. I think it's a nice option to have, I just like the looks and feel of the 642 better. Everyone's sense of balance and beauty and comfort is a little different, but that's okay, there are plenty of good choices out there. Most are pricey, but you get what you pay for.
Papajohn