In my opinion, the newer CZ 550's are 'modern' looking, brightly polished steel and actions also look more modern.
: The older BRNO's are not as higly polished, but are workhorses of good manufacture, slick up with use, and are much prized - by me, anyway. It does seem the general concensus is that the 'older' less refined rifles are more desirable. For me, it's the claw extractor & European style stock - they both work for me.
; Incidently, if it won't slam feed, you can polish the extractor claw with a dremel tool rubber polishing bit and slightly radius the outside rim of the case itself. This is generally all that is needed for reliable slam feeding, which is nice under some circumstances. I rarely put more than 1 or at the most, 2 rounds in the gun, and being able to to throw another into the port and close the bolt is handy on the rare occurance I want another shot.