I looked at both the S&W version and the Walther version side by side, and I like the Walther better. I can't put my finger on it, but the S&W just felt "odd". The Walther didn't.
Currently I carry a Colt Detective Special revolver, which oddly enough is similar in size to the P99 due to the cylinder bulge. Girp profile is different, and something to consider, but I carried a P228 for a pretty long time before that and that gun isn't any smaller than the P99. I've carried my P7M8 a couple of times, but I'd need a different holster for it. It's also has a bit more steel in it's construction.
I've heard about the trigger being different. How different is it? Is it unique to itself, or just similar to other stirker fired guns like a Glock, Spring XD, etc?
Lastly, what's the deal on "quick action" vs not?
Ross