They're now talking about what a slippery guy he is an can't be caught but we really haven't seen too much of that. He really hasn't had enough to do all season to establish him as a big bad guy.

Agreed that the prison stuff has been lousy, but the stuff with the Mexicans/Asian dude has been weak as well. They are a huge threat but everyone keeps putting them on the back burner - they put the bodies in the truck that the federalies take even though they know that will mean the death will be uncovered, Wynn Duffy lies to them about Boyd. For such a threat, people don't seem to mind pissing them off.

I think the end of the season will be Raylan killing Rappaport and his boss waking up and saying that it was indeed Kendall who shot him.

This season has been a lot of weak buildup. Picker was weak since he was basically confined to a hotel room. Rappaport's character flew under the radar for too long and was just trying to weasel his way into already shitty plans which didn't help. Ava and Boyd's love story came to a rather abrupt end which will likely end with Ava getting killed.

As others have said, a mediocre Justified is still better than most shows but this has most definitely been the weakest season and I'm almost happy that they are wrapping it up next season because I think they've gotten as far as they can with the current set-up.
Although I'd still like to see a Rachel and Tim spin-off