Berba did alright at Utd. He won 2 (???) titles and probably a cup or something. He was top premier league scorer one year and got a few in the other years too. He pretty much had a 1 in 2 goalscoring record.
Keane on the other hand....
If you just look at stats ok, but he became a bit part player and spent a lot of time on the bench the proof of which is he is now at Fulham which with all due respect is a drop from being a potential legend at Spurs.

no, some of the things he does are very similar. Zidane was more than happy to still receive the ball with one or two opponents around him, such was his skill at shielding the ball is something i noted, such a simple thing taught at schoolboy level, unbelievable balance for a big guy and great strength at holding players away, very rarely did anyone take the thing off him. Also just the simplest slight change of direction, was enough to just wrongfoot a player to go past them.