Yes. They can suffer from not feeding the last 3-4 rounds but not always. I don't have issues with mine in either my M4 or my G&G SCAR, buddy runs them in a G&G GR4 G26 no problem, another runs them in his CM18 too.
I use just the plain "bravo" type hi-cap and they are fantastic value for money 10 for £50 at LWA. I'd say best bang for buck hi-cap so far
Had to modify all of mine to make them feed in anything. Got them all working now, seem reliable enough.
http://store.specwarfare.com/en/gp-130rd-m4m16-ball-ball-mid-cap-aeg-magazine-w-handle-black I'll probs get these instead, they look better
