I have t2i and bought 6d about two weeks ago.
I'm still learning about 6d but 6d is better in every aspects.
Worth for the money? Not sure.
My t2i is good enough for my purpose.
If I had no camera, I would buy t2(3,4,5)i over 6d(too much money).
But I would pick 6d over 7d, if I have enough money.
Again, 6d is very solid, powerful camera (for me) .
