I have both, an STG takedown and a Mac 10 with the Lage goodies as you put it. I find the Mac is a lot of fun, particularly with the 5.56 upper or the extremely high cyclic rate rate uppers. However the STG is a more polished and ergonomic package and 80% of the time it's the one people I shoot with like the most, it's longer stroke and layout makes it so anyone can just use it. Also Brian is an A+ guy, he's answered any question I've had about it in short order. For the money you can't beat one of his guns.
The only thing I've found is that it does *not* like L7A1 ammo, and that's literally the only ammo I've found that it doesn't care for at all. Thankfully extractors are cheap