Most overrated that I've watched is probably Cole Kmet. Dude is a straight-line athlete who might have the least amount of strength I've ever seen in a 260 pound TE. I saw safeties put two hands in his chest and knock him back, consistently.
He's the classic "looks like Tarzan" guy. When he's running vertical routes down the field, you can see the Gronkowski comparisons. When he has to square up and block someone, he looks like his body is hollow. When he has to gear down to cut or turn upfield, he looks like old-man Jason Witten.
Speed plays at TE, and his height/weight/speed combo is very good, but he is a 2nd or early 3rd round gamble IMO and that's in a bad tight end class.
And several thoughts I have on the safety discussion here:
-I think the part people tend to miss about Delpit in the usual "He's a ballhawk! He can't tackle!" back and forth is that instincts are what translate most to the pros, and Delpit is really smart. The tackling scares me, and I don't think he's anything special as an athlete, but I also think he'll end up playing 10 years in the league simply because he knows what he's doing and where to go. As I've said before, my best comparison for him is probably Eric Reid.
-McKinney played about 60% deep or in the slot last year and 40% in the box, so the characterization of him as a box safety baffles me. He's a true "multiple" DB. For that matter, Delpit played 18% of his snaps in the box too. People typecast McKinney and Delpit based on the SS and FS besides their names on the roster, but LSU and Bama used them more fluidly and the NFL likely will too.
-Winfield is getting hype after his 40, but we knew he was a baller when healthy. The question with him has always been injuries, and I don't think that gets mentioned enough. He is a Sean Lee-ish type of health risk.