Realistically, having shot both, the CZ is what you want.
That being said, as a result of personal preference, I sold my Scorpion and kept my CX4.
Trigger: They both suck out of the box. The CX4's sucks more. You can get an aftermarket for it that makes it pretty darn good, but it's not cheap.
Ergos: The CZ is altogether more "rifle like" than the CX4's thumbhole stock. The CX4 feels smaller and more handy if we're comparing it to the Scorpion rifle.
Accuracy: About the same really.
Mags: CX4 wins here in my opinion. Cheap metal magazines over the CZ's plastic ones. Likely lots of surplus ones in the near future as the military phases out the 92. The CZ are higher capacity standard though.
Sights: The CZ wins. The CX4 has horrendous sights. They're usable, but it really shines with an optic. The Scorpion sights aren't bad at all.
Price: CX4 will come in cheaper, but putting in a new trigger kit bought and installed at almost $200 will make them about the same.
Reliability: I didn't run the Scorpion hard when I had it, and only used brass cased stuff, but I had no problems with it. My CX4 is high round count and still eats aluminum and steel cased junk when I'm too cheap to feed it brass. I think they're both fairly reliable.
SUPER TACTICAL OPERATOR RATING: The CZ looks cool and will attract women. When I had mine I always made sure to wear my wedding ring at the range. Even some dudes were offering to buy me a drink.
It also has lots of rails from the factory for mounting lasers, flashlights, flashing lasers, AFG's, VFG's, and PEQ's. It also has a factory threaded barrel.