In a studio situation the higher pixel count will give you higher IQ, the larger sensor only going to give you thinner DOF in your position. Get t2i if you want some extra dietail.
John.
I respectfully disagree . Out of 5 or so things that go into IQ, pixel count is just one. I agree in a studio situation I am just splitting hairs that are difficult to see. Any of the canon bodies, old and new, in a studio situation, should give excellent results.