I just checked one out at a LGS today, just dry firing and handling.
It really is quite impressive how small they were able to get this 10+1 9mm to be. And although the grip itself is very small in my medium-large hands, it still feels like a solid purchase and not oddly small like on a Glock 43 or one of those micro Kahrs. The trigger (any least dry fired) feels quite good , a simple makeup and break, probably smoother overall than the P320.
I am really not in the market for this pistol, but it is quite hard not to want one just for the achievement that it is as a platform. If it holds up and proves reliable and durable, then I really do believe it is a major step forward in carry pistols. I still probably wouldn't carry one appendix like I do my grip-safetied SA XDs and DA/SA CZ PCR. But it truly is a handy little nine that holds as much as my state-limited-capacity full-sized 9mm guns. At the very least, I think it would make an outstanding backup gun discreetly tucked away or on an ankle. A 10+1 rd 9mm that's smaller and lighter than a Walther PPK, and probably shoots better as well? Heck yes!
So after checking one out, my first impressions are kudos to Sig on the design. May have to pick one up once all the hype dies down a bit. But it's worth the hype, IMO.