I think he slides around in the pocket better than any college quaterback I have seen in recent memvory. I read that the abiltiy to move around in the pocket is one of the most important traits that NFL GM's are looking for.Another thing I like about him is that if you watch him play a lot of his success comes with traffic in the pocket. Not necessarily guys close to sacking him but him having to be aware of it.
Some of the recent college QBs who have come out to big fanfare have played with dominating o-lines and are able to comfortably sit back there waiting for their receivers to get wide open. Penix has a good OL but he still has to frequently move to find open space to throw from and to pass the ball earlier than some of the others. This also means his reads need to be quicker and his throws more precise.
When these guys get to the NFL they aren't going to have big, clean pockets to work from.
I expect him to go very high in the draft.