Generally they are reliable. They can be picky about mags so stick with OEM, no Promags or similar.
The 220 is like the S&W 4566
I'm not sure when the 220 carry came out. There was about a decade, between 04/05 & 13 where their quality dropped across the board. You either got a good gun or you didn't. There was restructuring, outsourcing of small components, faster and cheaper manufacturing. If you were the type to shoot a box or two every month you wouldn't notice the problems. But if you did high volume shooting they showed up pretty quickly. At one point the Secret Service dropped all Sigs when they started experiencing frame cracks around 5-10k rounds. The Sig Patrol rifle V1 was desester, even for the casual civilian shooter.
Either way the old CEO is out, a new one in, quality has seemed to be getting better and consistent. I tend to stick with the old German ones.
I have shot every 45acp ammo (standard pressure) I could get my hands on and the gun just eats them up, including steel case. My only complaint about the steel case is that the mag won't fit more than 4 or 5. I'm not sure if it's the mags or the dimensions of the steel case or both but they stop at 4 or 5 (can't remember) and you can't fit any more, which doesn't bother me since it's range ammo
One more thing. If it's the older German one you should stay away from +P ammo.