This one might be a little controversial...

I'm pasting just the relevant parts, but there's a longer, fairly critical article at the source.

From The Daily Beast:

Lautner may be hot now but most insiders see Pattinson as the stronger actor. And Lautner has irked at least one high-profile producer by dropping in and out of many projects in recent weeks.
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While Roth is clearly annoyed at being "jerked around," others say it might make sense for Lautner to book projects fast. A number of Hollywood insiders—agents, producers, executives—are skeptical about his long-term prospects; one producer says dismissively that Lautner appeals primarily to "little girls and gay men." And a leading agent says Lautner reminds him of The Situation from Jersey Shore ("It's all his abs") or "that blond dude from Blue Lagoon," a heartthrob movie from 1980.(The dude in question was Christopher Atkins.)
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Meanwhile, the 23-year-old Pattinson may be the tortoise to Lautner's hare. He and Lautner "actually have very different views of what they have in mind for their careers," says an executive who works with both. "Robert is much more about the artistic parts than the big commercial parts. . . Taylor was a child actor and worked in the commerce of our business." Indeed, Lautner has been acting since he was seven years old and got his first big movie break in 2005, in The Adventures of Sharkboy and Lavagirl.

Clearly Pattinson is looking to make more artistic choices and build a long-term career. (Between Twilights, he's set to star in Water for Elephants based on the historical novel by Sara Gruen, along with Academy Award winners Reese Witherspoon and Christoph Waltz.) "The spin his people are putting on it is that he wants to do this for 40 years," says a talent representative. So Pattinson is looking to actors like Johnny Depp and Leonardo DiCaprio as models, and some think he has a shot. "Pattinson is the more accomplished actor," says one studio executive. "I think he's more of a movie star as opposed to a hunk. He's got a better look."

SOURCE