It's a question of reliability. Every shot out of my finely tuned AEG is the same and I eat GBBr on the field. Also, mag reloads take about half the time and you don't smell like gas.
Of course, I've hit that point where I'm able to do anything mechanical or electrical to an AEG so my view is a little biased.
GBBr feels way better, though. My M14 is sweet as fuck to fire.
Age Verifier - Lower Vancouver Island
Brotherhood of Nod - Nod Prime || Vancouver Island Airsoft League - President