Having owned, used the HK release and being a southpaw I can say I like it is way better then C7 mag changes. The HK mags are soo much better then the stanag ones. Matter of fact the HK stanag mags are about the ony ones worth their salt. Don't get me started on the ####e stanag mag issues I've seen on service weapons, it is often the weak link. The G36 style mag release is awesome to say the least and it ambi.
Stanag is an old standard which many of the new NATO rifles no longer use. I kinda doubt it is the way of the future in weapons development. I'm pretty sure NATO cares more about the ammo then the magazine, plus the Czechs don't want to appear to be too much of a threat to Russia.