I have the UTG, and it is most definitely "not" the same thing. The AGM is kinda thrown together... I can't say much more about the UTG, but it seems to be much higher quality. (Plus its compatible with Maruzen parts!)
Just remember that its not compatible with ALL maruzen parts. But it is for some of the parts that the Maruzen L96 can take. Just dont be surprised if the gun breaks after long use because the gun isnt build with Maruzen Upgrades in mind and the gun may have a few stress point and break. But, then all you have to do is purchase a Maruzen L96 and throw you upgrades into it . Also, dont be surprised if you have to purchase a new trigger/trigger sear because even Maruzen break after time but, like I said before, Maruzen's are built with upgrading in mind. This means UTG's life span is shorter than the Maruzen.
Silly monk, UTG just rebrands everything, because, well, that's just what they do, oh well. For your sake, I hope your gun continues to perform for a while, as most UTG/AGM/Well/Some retarded name L96's have a 3month lifespan after which they decide it is time to break in some shape or form.