Having just gone through this, I give the following observations:
I bought two plates, one aluminum and one steel. The aluminum one arrived first, so I installed it. It was completely flat in top profile, had the correct bottom design to marry to the gun, and had a slight cut out where the ejection port is. Added a Holosun 507Comp and all is well.
The second one arrived much later, but it was nicer - all steel, and matching profile to the CZ top design, and a deeper cut out for the ejection port.
Maybe 2000 rounds later, I happen to check the optic and find it just slightly loose - at the attach point from the plate to the gun. So, not really liking the design of the flat topped plate, I moved to the steel. Did all the cleaning, alcohol wash, and locktite prep, the steel is operating fine after maybe 500 rounds.
If this is too cryptic I will add photos, but I do recommend the CZ Parts original design steel plate. It was sold out when I ordered, but they accepted my order and it shipped in good time. Packaged well from Czech Republic, no problem with shipping or receiving.