I've got a 2011 5.0, one of the earliest builds, I think June 2010. Initially I was concerned with the shift quality so I changed to Redline MTL fluid and the barton shifter w/ bracket.
This improved things for a while, but slowly and steadily they've been getting worse again. However, the symptoms are different now. Before the shifts were just clunky and inaccurate (deflection). Now, if I'm rev-matched they are smooth as butter, but any other time they are horrid.
Beyond that, I've noticed the "brick wall" going to 1st/Reverse from a stand still. And more recently noticed that sometimes when I'm pressing into first from a stand still the car will actually start moving forward a smidge. So I'm starting to think this is a clutch issue and its not disengaging.
Any ideas where to start? Could I just flush fluid and maybe change the clutch line? Or is this probably the pressure plate bolts issue and I'm going to have to drop the whole tranny?