Ruger = Ruggedness
S&W = Pretty
That's the general consensus I've come up with after owning and shooting several of both. Except I don't always find S&W's all that much more "pretty". My latest Ruger was in fact a GP-100, but in .22 L.R. It's a beautiful handgun. In the first outing I had 2 people come up to me and ask, "Is that really a .22?" I like the brushed Stainless Steel finish on the Ruger guns better than I do the S&W models. The S&W's seem a bit more "blotchy" in their appearance. They're not brushed, but they're not polished either. At least not to the degree the Rugers are.
I looked long and hard at the S&W 617 before I settled on the GP-100 .22. That is not to say I won't own a S&W 617 in the future. I just thought the Ruger was the better choice based on appearance, feel, and overall ruggedness. If the trigger on the Smith is any better, I don't know. The last thing you want to do at a gun shop, is to start dry firing brand new rimfire revolvers.
When I bought my .500 S&W, I settled on the Magnum Research BFR. I just saw zero need to own a double action .500. Especially when, at the time they were having all of the problems with the guns double firing. And also a lot of the early ones were having lock malfunctions. My dealer told me he got the first 3 S&W .500's he sold back because they all locked up. Again, at some point I might spring for the S&W 4" model.... Just to have. It appears they've got the bugs finally worked out.