I have one of the 452s (2016 models), and it's by far the best shooting .22 rifle I have. The wood is okay, it looks like they stole the blanks off Ruger's woodpile, but more importantly, it shoots well. With good ammo, it's not rare to shoot under a .5" at 50 yards.
I had one of the very early 455s, and it was a serious disappointment. I tried it with all three chamberings, and it wasn't anything close to this 452. Last year, I bought a later (C-prefix) 455 Scout that shoots "almost" as well as the 452, but the key word there is "almost", it's not quite there, but it IS a lot handier for hanging out a truck window. The Scout outshoots an RAR Predator .22LR I have, it's a keeper.
The newest 455s are coming along quite well, I think, but based on those three CZs, I'd still pick the 452, given the choice. I wouldn't be scared of a new 455, though, they are doing better now.
I like that little Ruger, too, but they have a very long ways to go, to catch up with the CZs.
