Depends on what you look for. Haden really bombed his combine drills and was considered "slow" by some. However his game tape has always been fantastic.
Gilbert struggled his junior year but was really great his senior and sophomore year, and his combine performance was incredible.
I would say that Haden showed better, more refined skills, but Gilbert is the better long term prospect. I would probably take Haden over Gilbert, but it's close.
I flip it.
Always thought Haden could cover and tackle, but was never going to be good enough to get takeaways (which is weird because he has QB sized hands) and was always going to get burned by faster guys (if Joe Haden gets beat, it's either a hold or pass interference.) But Haden was going to never be bad. A really safe corner, to me, and it was why I was admittedly aggravated by the pick. I want Earl Thomas. Both ended up being top at their position.
Gilbert to me has that pizzas that a Revis or a Sanders or a Peterson has. When they get his technique up to Haden's level, Gilbert will absolutely be a better player. Long, and incredible range. Don't really think there's a wide out in the league that just torches him. Dude's gunna ball.