Wow it's funny that such a simple question turned into a pissing contest!
To answer Hata's question;
Both G&P and CA have been in the AEG business long enough that their products can be considered separate and unique from TM. Yes they all use a mechbox, yes TM pioneered the technology. But at this point insisting that any company other than TM is a clone is like saying that all other car manufacturers are "clones" of Ford.
You're better off to think of the AEG world as a collection of two groups of companies - 1st Tier are those companies that design their own products and innovate, like TM, G&P, CA, Real Sword, etc. 2nd Tier would be the chinese manufacturers who indeed to "clone" AEGs, regardless of who originally manufactured them.
What is important for you is to do research on AEGs you are interested in, attend some games and get some "hands on" time with some etc.