I have owned the T2i, and I OWN a Nex-3...
I also use a Canon 50D... When I compare the quality of the photos I take with my 50D to the T2i, its hands down, the 50D is the winner.
So I sold the T2i... I also Bought and sold the T3i, the T1i, and the 10D.I find that the reason I still have the Nex, is because of its ability to use BILLIONS of different lenses, (albeit in manual mode only) by purchasing a simple adapter for each of the lens types.
I made the mistake of LEARNING the hard way, what makes lenses great... By purchasing dozens of Lenses for My Canons... easily costing me a few grand... and out of the 40 or so Lenses I have owned for my Canons, I only still have 3... if that means anything.I have also purchased nearly 50 Vintage lenses, from the BASIC minolta 135mm 3.5... for under $10, and an adapter for $9.... all the way up to a Pricey Fujinon 50mm 1.2 c-mount Lens... and have found that Without the NEX, I wouldn't be able to take half the pictures that I do.
Personally, if you are looking to be the one taking the best pictures at a soccer game... They both have great Auto Focus Lenses, pretty much the same sensor quality, and make you look BADASS... but if its a hobby, and you want to really FEEL at one with the camera, being forced to use Manual focus, on the best lenses around... The nex it the best coice, hands down.

