Really nice breakdown. 100% agree with Tannehill, particularly in terms of 2010 vs 2011. The way RT has been hesitant as a senior reminds me of Brian Brohm's senior year and he never really got out of that.
Os I really liked the first couple of games I watched - but the more I watched, the less I liked him. Took too many sacks and just doesn't seem to see who is going to be blitzing enough of the time. Love his feet for a big man, made some very nice deep throws (thinking the Oregon game particularly) and I loved his fire in the Bowl game waving off the FG team to go for it on 4th down when the team really needed a spark. Some are worried about his long release - but looks OK to me. Vertical offense guy.
On balance, if I had a gun to my head and had to pick one of them, I think it would Osweiler. But I'd take Kirk Cousins ahead of both!