I'm not really sure how much of a geek Abrams actually is and how much of it is a calculated persona. Whedon wears his passions on his sleeve and Serenity is a masterpiece next to Star Trek. He can write and knows how to make a film.
Abrams movies all look like and episode of TV. Everything shot hand held, in close ups and mid shots. There's no sense of the 'cinematic'.
I don't rate him any higher than a Peter Berg, Joe Carnahan, Marcus Nispel or any other jobbing director whose movies are largely indistinguishable from the other.
I wouldn't harp on about it so much, but he's seems to be heralded as the saviour of the blockbuster.
Here's author China Mieville's take on it -
I've never met [JJ Abrams]. I am not a member of his fan club or anti-fan club. I disliked Cloverfield a very great deal. I disliked Star Trek intensely. I thought it was terrible. And I think part of my problem is that I feel like the relationship between JJ Abrams' projects and geek culture is one of relatively unloving repackaging - sort of cynical. I taste contempt in the air. Now I'm not a child - I know that all big scifi projects are suffused with the contempt of big money for its own target audience. But there's something about [JJ's projects] that makes me particularly uncomfortable. As compared to somebody like Joss Whedon, who - even when there are misfires - I feel likes me and loves me and is on some cultural level my brother and comrade. And I don't feel that way about JJ Abrams.