Which type is better? Well its for what ever suits you best and after i am done explaining maybe you can choose which is right for you because its about whatever your style fits best. I personally own a couple from each side. I will also be talking about normal standard aegs not blow backs or the rumored erg series to be coming out by KWA. Lets start with the major difference the power supply. aegs run on a battery and gas run on basically propane or green gas. for a gas gun you have to fill the magazine with gas as to putting a battery in the gun. The operation of gas guns are all more or less a valving system that gives you a realistic action of blow back having some recoil with the bolt moving back and forth like the real gun operation and the bolt will lock back like a real gun when you need to reload. The downfall is you only have 30 rounds per mag and gas lasts almost two mags worth of bbs. as too an aeg which will go through a couple thousand rounds on one charge but you do not have any realistic functions of the bolt or bolt lock and recoil like the gas gun. Gas guns need maintenance more often but its very easy as to aegs need less frequent maintenance but its harder to do. Externally they look the same if its the same gun with same quality of coarse.Now its time for you to decide which suits your personality and hoped this helped!