I think a lot of people underrate and dismiss him simply because he doesn't have the 'right look', the fancy footwork, the mazy dribbling skills or the lightning burst of speed that most world-class forwards are usually blessed with. To them he's apparently just some decent striker in a good run of form. That is why, I believe, some rate him below the likes of Ibra, Lewa, Aguero, etc. They think he's just some lucky bystander living off bread crumbs dropped by Messi. I say, "F**k them". He has been doing the business long before he came to Barca, and with mostly average teammates as well. None of those other 3 strikers will be able to do what Suarez did with a mid-table Liverpool squad. He carried the team to a title challenge having a direct hand in a majority of the 103 goals scored and creating one of the most number of chances in the league.
He's not perfect. He's flawed. Often glaringly and frustratingly. But there is no other current CF on the planet that comes even close to having the importance that Suarez has had (and is currently having) in any team he has played for throughout his career. That's the bottomline. And if the Ibra-Lewa-Aguero fanboys don't like it, they can shove it where the sun don't shine.