I forgot to mention i do have the 50mm 1.8 canon but i feel it is a odd length for me i feel like its too long. I am borrowing this lens (the 17-40) basically until i buy the next lens. I am on a limited budget i basically have enough for one lens. I have about $1350 at the moment
If you feel 50mm is too long on your 6D, then you will likely feel the same about the 35 on your T3i. I'd go for the Tammy. After a few months, see if you've developed a preference - where you've used it the most (i.e., wide or tele end), and base your prime lens purchase on that.