Would be a difficult choice to make, and I have been pondering both of these choices as well.
I will point out that the muzzle brake that comes on the SGL is not an easy thing to keep clean, IME. At least not in the AK74. The carbon residue that builds up inside that brake is very stubborn. If the SGL had a traditional slant brake or muzzle nut I might be more inclined to get that one. As it is, I like the low price, but that is offset some by the presence of that brake.
The CZ is a neat rifle technologically speaking. IIRC, many of the internal parts of the FCG are made of plastic, which puts me off some.
If the price were the same I'd choose the CZ offering, but...
Sigh.