You can compare the two rims on aesthetics but they're really not on the same level of performance at all. CXP-22 is a great street rim though, I wouldn't want to lock up anything much higher end or ride anything much lower end. It's tough, light, and inexpensive.

Off topic, but if anyone's interested a guy I know here has a NOS Mavic Reflex (old name for the Open Pro) laced to a higher end Campy hub, just a front wheel for $65. Pretty good deal IMO. You could save a little bit and build your own rear or just go mismatching.