i personally have not a lot of experience with aegs (Evans helping me change that) but with gbbs at least the pistols that ive worked with (we1911, TM 1911, KWA glock, KJW glock, KWA USP compact, a little with the KWA p226s and M93rs) i have had very little problems but i have seen problems with aegs and the gbbrs such as stripped gears or for the king arms gbbr m4 from what i understood an internal part of the blot kept breaking consistently on all of them so i am all for gbb handguns but a little iffy on aeg or gbbr just on the fact that i know how to work on a gbbr better than an aeg.