i see gervinho as being more useful in the league than nasri was for us (only going on nasri's actual past performances, not his current or future potential), whereas nasri would be more useful in big games, CL, etc., where we need top quality to get us goals.
gervinho's more of a flat track bully due to his quickness and pace, but at least he's bullying somebody. aside from a 3 month stretch, nasri didnt actually do anything. they're very different players, though.