I've never had a DW gun, or even seen one at any sporting goods store or gun dealer's shop. Nor have I ever seen one at the range. They've been such a on-again, off-again company that most shooters have just gone on to something else.
However, I do have several Rugers and Smiths, and I can recommend either.
The Rugers are tanks that are built to last for your great grandchildren to shoot. They will need a trigger job. Great grips, too.
The S&W N-frames are terrific guns, too. True, you are not supposed to use the Buffalo Bore Mega Blasters in the S&W, but unless you live in Brown bear country, why would you need to? For 95% of us, these rounds are overkill anyway. I've got more .44 mags than I can shoot (no, I'm still not getting rid of any), but if I were getting another, I'd go with the S&W Mountain Gun, but alas, you said you have to have a 6". So that means 629.
You can't go wrong with either. Just handle them all. Pick the one that feels right in your hand - weight, balance, grip, etc. The deer won't know the difference!
(Oh, I do have a Colt Anaconda, too, but good luck in finding one of those now. Plus, they're not worth the asking price as far as I'm concerned.)