My Czech friend has a Brno 452. Back in the day when they imported the CZ 452 with Brno markings on it. The CZ 452 is just a Brno Model 2. Anyways, I love his Brno 452. Yes the trigger is adjustable. He has his set to hair trigger pull. You just have to look at it and it goes off. Super accurate because it surprises you every time it goes off. A lot of people don't like it like that, but once you get use to a hair trigger, you never want to go back to anything else.
I have a Ruger 10/22 and I can understand why some people can't put up with one and would want something else. You pretty well have to sink an additional $100 into your stock 10/22 to get it to shoot like a CZ 452 or 455. That being said, i still love my Ruger 10/22. It’s got me 2 grouse last hunting season just from me driving home from my range which is located out on the logging roads. The barrel changing process on the CZ 455 is a pain in the ass so I wouldn't look at that as a plus other than its easy to re-barrel it if you can even manage to shoot 50,000 rounds wear out the barrel. Apparently the 455 is slightly more accurate than the CZ 452 as claimed by CZ. I really want to get a CZ 455 LUX FS in .17HMR. I already have a .22LR and there is no point in getting another one. What’s sweet about the .17HMR is you can get the same size groups a .22LR gets at 25m at 50m and then the same size groups at 100m that a .22LR gets a 50m. (Assuming it’s a nice day out with not too much wind.)