I have one that I use for CC when I need a really short bbl. and 9mm capability. That said, it's got Sig quality built in and accuracy too. 7 yd groups run to an inch from a Weaver stance with my 70 yo eyes doing the steering.
It is a heavy gun however, definitely not a 'pocket' pistol by any means short of a heavy winter parka. I just weighed mine at 24 oz. fully loaded with a 6-round mag. I carry it in an OWB holster that rides high on the belt line. Mine has Sig's version of tritium sights...a definite plus for any defensive handgun in my opinion. The grip is short with the 6-round magazine in place, allowing only a two-fingered hold, but I've found that's good enough to get those 1" gps. previously mentioned.
I do have a pair of 8-round mags with the poly grip extender that allows a full grip by the shooting hand, but in reality, they do not improve accuracy...however the gun does feel more secure in the hand.
Reliability has been ~100%, but only after it went back to Sig for light firing pin strikes. Mine is the early model, a P290 without the re-strike capability...I don't feel that particular feature is really needed since I train to clear any malfunctions at first indication. I don't attempt a 2nd trigger pull feeling that this is a waste of truly valuable time. Analyze, tap & rack is a response IMO.
Nor do I have the available laser attached to mine, since it's a belt gun, and I use it for CC, not as a night stand home defense weapon.
One drawback, for me at least, is that the P290 does not take down using the usual Sig take down lever. Instead, you have to align a take down notch with the slide stop pin to do it; a two-handed dextrous operation that's a PITA for me. A review of the take down can be found on U-tube and I strongly suggest you look at one before breaking the gun down for cleaning.
All in all, I like it for the niche it fills in my daily carry regimen. Here's a pic in one of my holsters carrying in the FBI 3:30-4:00 position.
That about does it, HTH's Rod