I have both the 4.2 inch SP101 and the Wiley Clapp 3" GP100. I will have the new GP100 Match Champion in the next few weeks or so since I've been going heavily back to revolvers since I left the field. The 4.2 SP101 is quite pleasant even with .357's. The longer barrel does mitigate a lot of the blast and flip my old snubby had. Weight is not an issue. The gun is easy to carry. The SP101 is a bit easier to carry, but the WC is a more comfortable shooter, although not by too much. They really aren't that far off on the weight. I know on a scale there is probably a significant difference, but in your hands or on your belt it's not that noticeable, at least not to me. A good holster makes both easy to conceal for me, a medium-framed guy.
It's not a snubby and doesn't handle like a snubby, so don't expect that. It handles like a mid-sized gun, or at least I feel like it does. The Wiley Clapp handles quite nicely, too, and is extremely quick in the hands. If I were you, I'd get a 4.2 inch SP101 if you're in the market for one. If you're undecided between the 4.2 inch SP101 and a GP100, wait until you can hold a WC or MC and decide from there. I wish I could say the choice gets easier once you do, but I'd be lying.