Lack of ball skills with Purifoy, which is why he's never had an interception. He's stiff in his hips and has trouble breaking down properly in space to make open field tackles. He's a very rigid athlete with little fluidity to him. However, he earns high marks with his explosive physicality, and he's a great special teams player. Questionable demeanor and decision making off the field dings him a little bit in my eyes. He looks like his skillset would be a better fit at safety.
Roberson is the more pure corner and better cover guy despite Purifoy's hype.
Hargreaves is going to exceed both. He's already a terrific young corner. Reminds of Joe Haden early in his Gator career when he was the first true freshman to earn a starting job before the season even began in the history of Florida football. Hargreaves has the ability to be that good. Very similar builds, style, abilities, and mentalities.
Purifoy essentially got his first career INT as I was typing this post. Returned it 42 yards for a TD. Also had a sack, FF, and 3 PBU's.