Over a longer period of time, absolutely. I wouldn't trade their careers for Gronks at this point. The big thing is Gronk has been absolutely unable to stay healthy. By the time we get to the playoffs, he's either very limited, or completely out of action.
But when healthy, I've never seen a weapon like him at TE in my life. He's tied for second fastest (with Randy Moss) to 50 TDs among pass-catchers in NFL history. He's just a completely ridiculous weapon.
And he's only 25 years old!
If he can stay healthy, I wouldn't trade him for any pass-catcher in the NFL. Unfortunately, there's NO reason to believe he will stay healthy.
(NFL Records so far
NFL records
Youngest player with 3 touchdown receptions in a game: 21 years, 214 days (2010, vs. Pittsburgh Steelers)
Youngest player with 3 touchdown receptions in a game, playoffs: 22 years, 275 days (2011 playoffs, vs. Denver Broncos)
Most touchdown receptions by a tight end, season: 17 (2011)
Most touchdowns by a tight end, season: 18 (2011)
First tight end to lead the league in receiving touchdowns (2011)I
Most receiving yards by a tight end, season: 1,327 (2011)
Most offensive touchdowns in first two seasons: 28 (Tied with Randy Moss)
Consecutive seasons with 10+ touchdowns by a tight end, 3