I've got a 452 Varmint that I've shot for a couple of years. It's a good shooting, well made rifle.
I got a T1x a while back, and put a T3 Hunter stock on it. The rings in the pic below
are Warne high rings, I've since switched to the same ring in a medium height to get the scope lower. I added a Beartooth comb riser kit for a better cheek weld, that seems to be a standard item for me on any rifle that uses a scope and doesn't have an adjustable cheek piece.
A lighter trigger spring and a shorter set screw brought the trigger to roughly 1.5 lbs.
I'd have to say the Tikka is a nicer rifle than my CZ 452, once the OEM plastic stock was replaced. Metal machining and finish is better, night and day really. The Tikka has a leaps and bounds better trigger, a far better looking barrel crown, and it seems to shoot better than my CZ.
The Tikka loses ground with the bottom metal being plastic, and feeding from the magazine isn't as smooth as the CZ. Unless you have fingers the size of cigarettes, single feeding the T1x is going to be difficult.
The mag is fairly hideous too.. and mine only holds nine rounds for some reason??
The barrel attachment method on the Tikka is a bit unconventional, but I think it will be just fine if left well enough alone. From what I've seen online, all that controls headspace is the three set screws that lock the barrel into the receiver. No threads, no shoulder to butt up against. It was never intended to be a switch-barrel rifle like the CZ 455 or Sako Quad.
My CZ is getting the summer off to lounge in the safe while I shoot the Tikka. It's impressed me with how well it shoots.
I wouldn't suggest you sell your 452 before you buy the Tikka, but I do think you might want to try one, particularly if you're not going to use the OEM stock. It's definitely the weak link in the overall package.