I had to polish the chamber, ramp and the extractor on my Curve to get it to function correctly, and I bought it used. It was very clean, so I'd imagine the previous owner tried to put a box of ammo through it and had so many issues that he/she gave up instead of sending it to Miami. I had similar issues why I first tried it, only worse. Lots of FTF, a good number of FTE. All in all, very unreliable. Like a broken gun. I read somewhere on here someone had to do some polishing and that's what I tried. It'll now eat anything I put in it and it's in my carry rotation, mainly for what I bought it for: when I go jogging (high humidity/sweat etc). As for specific ammo, it's been a long time. The range offered SigSauer of all things. I also bought some self-defense rounds and some Wolf steel-case. Not a hickup with any after the treatment. Good little gun, and surprisingly accurate with the laser. Only complaint I had was that the brass went, well anywhere. Could come straight back to my face or well up over my head to my right. Not really an issue for me personally, though I wouldn't want to get a casing to the eye in a self-defense situation. That being said, I rented a Ruger LCP at the range, before buying the Curve, that put just about every casing square in the middle of my forehead, and my wife's Bersa would sometimes do similar.
I opine that, given just a bit more QC at the factory for the chamber and extractor, plus some better marketing, the Curve could have really been a hit. When I sent in my PT145 for the claim, the options were a Curve or a G2C, and I really had trouble deciding.
TLDR: polish the ramp, chamber and extractor and go shooting. You might be really surprised.