Luckily I don't bite.
There're several disadvantages. First off you can't write a game in less than a day (i.e. prototyping is only fast if you've already built a little framework with collision etc.), secondly shaders are a pain (at least in the beginning)

On the other hand you can code oop which makes a lot of things a lot easier.
Engine is open source so you can change whatever you want.
No license

I like Irrlicht but for beginners A6/7 is certainly the better tool and if you're in a hurry you should take one of the licensed engines out there.

Anyway good job Slin.