I've had my CZ 452 16 years and i would not part with it. I tweaked the trigger because it was a bit heavy .
I also renewed the extractor claws and bolt spring because the spent cases were not ejecting but it turned
out it was the fault of the winnie subs i was using not the bolt.
I have also just bought a new CZ 457 and also tweaked the trigger. Very good guns for the money.
But i have never shot any other .22 rifles.