Gun reviews can be found all over the internet, regardless which search engine you use, a different combination of search words can yield different searches. Let me keep it short and sweet, for the bulk of it, AEGS are simple motors that drive pistons that compress a spring to expel air to propel a BB down a barrel. How you want that set up to look is up to you. There are many brands of companies out there that make airsoft guns, how much you pay maybe relevant to the quality you receive.
This is your second thread about the same subject, you already have one thread asking the same question.
http://www.airsoftcanada.com/showthread.php?t=63278
Buy a Tokyo Marui, if youre a cheap ass buy a JG. Theres your answer for you, accept it or dont.