I had a hard time making that decision myself, as I love both the CZ 75 line and the XD line, and I shoot both guns well. You really can't go wrong with either, as they're both reliable, highly accurate firearms. Here are the things that pushed me toward the CZ:
1) I already had a CZ 75, and I was told the RAMI takes CZ 75 mags, which is nice for range use.
2) The XD slide is very tall and blocky, and I think it would not conceal as well as the CZ.
3) The CZ is significantly cheaper.
4) The CZ can be had in polymer or alloy framed versions.
Other potential CZ advantages:
1) "Cocked n' locked" carry (manual safety) if you're into that.
Some XD advantages:
1) No manual safety to fiddle with, just point and shoot.
2) If it's a CCW gun, LaserMax makes an internal laser sight for the XD that replaces the guide rod for the XD, but doesn't make one for the CZ.
3) "American" company - actually made in Croatia, but owned by Springfield, if you count that as an advantage.
Both come with 10 round and extended grip, hi-cap mags, so you can get a full grip on either of them if you so desire. Or, you can just use the flush 10 rounders and conceal it more easily. Really, it's like deciding between a Mercedes and BMW.