The VA series is a bargain you wont find anywhere else. You get a reputable product (check the hammer test) that is consistant with the internals. No one else can get that price on that quality, G&G included. If you like the M4-S do not buy A&K from S8 as the internals are garbage plastic as brittle as a candy cane from 1999. If you like the 416 and go G&G (they do have nice product) be prepaired to replace piston head, had two fellas that we did this for smile for weeks
That said look at some pimped pics of those models and choose. You'll love the one you get, thats what always happens as long as it shoots nice.