Hey, congrats. I almost ended up with a SW99 compact myself actually (last year) when I couldn't find a P99 for a while. Good gun - I like my fullsize SW99.
I found I couldn't use the flat base mag very well, so now I have the extension on both of my mags. Love the little compact. Let me know what ya think of it. It does have a bit of a snap to it. But its not bad, and the gun is very accurate despite that. The fullsize ones have less recoil, obviously.
And, U can always get the fullsize mags if ya want higher capacity for it.