I owned both. Both where awesome guns. Best value non-restricted rifles on our market by far. Even at $1200, Id rather own 3 of them than a single Tavor. The CSA is better if you intend to do a tactical build. The CZ is best left original. The 858's problems are well known and very easy to fix yourself. Can even fix it while you're out shooting. The welded bolt tab isn't needed to fix the CZ Gremlin type 1 or 2. The Welded bolt tab just makes it so you can have a lighter trigger pull without suffering from the gremlin. The CSA however, needs to go to the warranty center to be repaired. When my CSA blew the bolt up, I sent it to Movie Arms who is no longer the warranty. However, the warranty work was fast and never had an issue afterwards. I've heard the new warranty place is okay. The good part is CSA has 5 years of warranty and they really stood behind their product. Overall, I rate the CZ slightly higher than the CSA but only slightly.
lm a heavy high volume shooter so warrenty to me ls securing my 1200$ investment.