Wasn't he a 2* coming in, so isn't he reailizing his potential already?
There are always some mistaken ratings, his was one of them. Even one of the service's evaluators said so in an article that I think was in the local paper. In that regard, he has outperformed.
When he showed up at UT and started eating Senior O-lineman's lunches on some days / some plays it became clear the evaluation services missed on him, and that he ought to be something special. The disappointment has been that pattern of eating O-line lunch one play and getting nuked on another has not changed since the first day he was at UT.
Usually a freshman who does that will slowly increase the number of plays they kill it on, while drastically lowering the number of plays they suck on. Hughes has done that a bit, but not to the extent is normally seen from guys that go on to be dominate every down players at this point in his career.