Just bought one myself! Couldn't pass on it for the money, and my K-.38 EDC is showing it's age. My M&P Shield 9 hasn't proven itself yet, but that's probably going to be a formality with a gun from a top manufacturer...not always though. Every company turns a lemon or two.
I am starting out with Federal 115gr Hydra Shok, Remington 124gr Golden Saber, and 115gr +P Speer Gold dot. These have proven track records, and are carried by the Local LEOs.
To "graduate" to my holster, the gun must run 300 rounds of ball, followed by 100 rounds of duty ammo flawlessly. (Would love to say 200 rounds of duty ammo, but this is a concession to cost.)
I also will have to consider muzzle flash from a 3" barrel, which might put the +P loads out early as it can be quite blinding at night.
Accuracy: Haven't shot it yet, but in a sub compact I am looking for 4"-6"/25yards rested, and "All shots in the upper torso" at 50 yards. Others will disagree with having a 50 yard requirement, but I have my reasons.
Ergonomics: So far my impression of the gun is...very good. It seems like the trigger group is carried low, causing it to feel very "tall" in my hand. Grip to trigger geometry isn't unlike a DA revolver, when the latter is gripped high. Comparison of grip, bore, and sight axis with my tiny little P3AT proves that it really sits quite low in the hand, just as low as the little KelTec in fact.
Trigger Has to be one of the worst I have ever had, and this is going up agains Rossis, Chi-com Tokarevs, Rugers in the DA mode...Maybe this is a one-off, but mine has the expected long take up, followed by a horrendous stage of creep, and a let off that is difficult to isolate from the creep. I really hop it smooths out during break in.