Wow, if I'd known about the rebate, I would've waited 10 months or so before getting mine at what now seems like a terribly over-inflated price of $365.
I got the 9mm version after test-driving it against several other sub-compact style handguns. The Shield simply fit my criteria better than the other guns I tried out.
Anyway, to date, I've put close to 1,000 rds through it. So far I haven't had a single failure or malfunction of any kind. About 400 of that was MassAmmo's Sasquatch 115 gr. ammo, and the rest has been a mix of WWB, CCI, and my own reloads.
As others stated, the grip didn't feel quite right in my hand, but a Hogue Handall with a couple wraps of grip tape underneath solved that for me. My only real issue has been the very stiff magazines springs, that eventually convinced me to get my first speed loader device, an Uplula, which has been as good as advertised.
I also recently picked up an Apex Tactical trigger kit (just the aluminum trigger without the replacement sear) just because I dislike plastic triggers. Apex claims that the trigger kit reduces pre- and over-travel by 20%. I have no way to verifying that, but it definitely reduces pre-travel significantly and seems to allow the trigger to break a bit more crisply. Trigger pull weight seems unchanged.
I just took a defensive handgun course using my Shield and it performed flawlessly. Of course, I did a lot more tactical reloads than everyone else, but I needed the practice anyway.
Normally I carry a 1911 in 9mm for EDC, but I have to admit my Shield is quickly becoming a favorite carry gun around here.