I've owned the CZ 550 Varmint Laminate in 22/250 for about 2 years now and couldn't be happier with it. I won't argue the rebarrel issue PC brings up because he is probably right. I'm just not familiar enough about that subject to comment.
However, I can comment on the feeding and loading of the box mag. I'll admit, I was a little disappointed when I first got it. The action seemed rough when feeding rounds. However, after 50-100 cyclings of the action and some oil, it became smooth as butter. I wouldn't use this issue to determine whether or not to buy one. As for the box mag, I like mine and have had zero problems with it. It's my only box mag gun, but it really doesn't bother me.
Accuracy wise, it's one of the most accurate factory rifles I own.
Either way, Rem or CZ, I think both are fine, accurate rifles. Just depends on your preferences. I plan on keeping mine for a long time.