It comes with a high cap, it's compatible with a lot of Midcaps I've tried, they just need the small plastic square near the BB feed on the mag. Battleaxe, Cyma, DE and Nuprol all work with it.
This was a while back, but I would say wait unless you'd like to try something new! It has issues, which I've had to sort out myself by sticking a magnet on the bolt in order for the hall sensor to work to allow it to fire.
I think it needs a couple more months before it's ready, but it's definitely an exciting platform.