These are the three games I watched of Guyton prior to the draft that molded my opinion on him. He's uneven against the run (but actually very good in the Oklahoma St. game) but the pass protection is what really sets him apart.
In these three games there were about 80 plays that I'd call pure pass pro sets, where I'm excluding some passes that are based off RPO-type action and quick game/tunnel screen stuff. Over those 80 plays or so I'd say there are at most 7 that I'd call losses where he gets beat, although he doesn't give up a single QB hit or sack.
Some of the competition isn't great but he went up against the best edge rusher from Texas a few times and Collin Oliver from Oklahoma St. who will get drafted next year.
Some of these reps are only so-so, but if you watch 2-3 games of someone like Jordan Morgan or Sumataia I guarantee you you'll see much worse. Morgan got whipped a bunch of times for sacks/QB hits in the clips that I watched of him, Sumataia was murdered against Texas who Guyton held up very well against, and even Tyler Smith was beaten for sacks/penalties a number of times when I looked at his last year in college after we drafted him.
There's plenty of technical issues to iron out but the natural pass protection ability is excellent, and if he has the same sort of work ethic/motivation that Tyler has I'm sure he'll be at least a borderline Pro Bowler.