I currently have both and I've had several Sigs in the past. The P-220 is an outstanding weapon. It will feed practically anything and is the better choice if you want to shoot lots of HP ammo. Accuracy wise it's a toss-up, the 220 and the 97 are superbly accurate out of the box.
The 220's grip is probably more universally liked being slim and ergonomic. It's also the logical choice if you ever want to conceal carry. I'm not a big decocker fan, but I perfer the decock mechanism of the Sig over the CZ. The Sig's SA out of the box will be much better than the CZ's, DA on either is not great.
Sig's are ridiculously over-priced for what they are, i.e. stamped sheet metal internals, etc., whereas the CZ uses forged internals and solid steel construction.
Kind of an apples and oranges comparison. I say get one, then save your lunch money and get the other.