EBB isn't blowback... it's a reciprocating motion that's generated by leeching some sort of mechanical movement from the geartrain.
Basically the bolt is drawn back on the piston back stroke and released to be pushed back by a separate spring. It makes a clacking noise but does not contribute anything to recoil.
AEG vs GBBR is a preference on play style there's no game that will restrict you on choice. While you can underload AEG mags to real capacity, the GBBRs provide a bit more feedback when they shoot. There's an inherent giggle factor when you shoot a GBBR vs an AEG.