Omg I know what you mean urban>.<
I was invisible, and trying to backstab a few medics/heavies, when all of a sudden i get lit on fire. I got WTF? HOW COULD HE HAVE SEEN ME?
and yeah.. :/
But what I usually play nowadays, is soldier! *edited*, the rocket boost (which I JUST recently learned how to do efficiently ;P) makes the soldier incredible 