I almost bought one when they first came out, but I'm glad I didn't now. If you go to rimfirecentral you'll see a lot of threads by guys who had problems with theirs. One member even sent in his rifle as a test copy because Timney didn't realize the triggers are different for the .22 LR and .17 Cal guns.
I even spoke with Timney late last year and they admitted they are still having problems. I would give them some time. Timney makes a great product, but they just don't have the CZ 452 trigger quite yet.
I ended up buying the Automation Solutions Adustable Sear, but have not installed it yet.