Someone said Vaas is underrated. Yes sometimes his intelligence as a bowler and variations, changes of pace etc, aren't appreciated by the public because he's not lightning, but I don't think he's underrated, most people who know anything about cricket rate him, he's brilliant to hold a team together wihtout much consistent support from other pacemen.
Sami's a very difficult one to comment about. He has alot good about his bowling, but I don't think the problem is him being underrated, its over-rated. No one else would get the amount of chances he gets, just in the hope that it'll pay off and he'll bowl one great spell and become consistent somehow.