I have the 455 varmint and I am very happy with it, my only complaint being that it occasionally fails to feed the last round in the mag properly. The bull barrel is instantly recognizable as more robust than the tapered 452 varmint barrel. The target-style crown is nice. The bolt feels smooth and solid.
I haven't shot the 452 and 455 side by side, but my target comparisons don't show a clear winner between the two. Both are excellent.
With a bipod and a 50mm scope, mine is a little chunky...but it has a great personality.
You would be hard pressed to get me to sell this one - which is exactly what I said about the 452 this one replaced