Everyone in the X-Division is better in the ring than anyone the WWE has right now. The only weak side to the X-Division guys in the ring is the lack of psychology, which is more the fault of TNA booking than the guys in the ring. Hardly any of the X-D guys have the mic skills to be stars in TNA let alone WWE though.
Abyss is easily the most talented big guy in the business right now. He doesn't have to work the stick because of his gimmick and in the ring there isn't a big guy who can hang with him.
Anyone not biased by one brand or the other should easily acknowledge that TNA has the best ring talent, but the worst mic talent. Hardly anyone in TNA has the attributes needed to be a superstar, which sadly rarely ever includes ring skills.
Of the pure TNA guys Samoa Joe is the one who, if he was inclined to goto WWE, would take over the world of wrestling. AJ Styles has the ring ability, but not the mic skills. Daniels has the ring skills and just barely has the mic skill to make the mid-card in WWE.
On the flip side someone like Shelton Benjamin has the ring skills to compete at a high level in the TNA X-Division but just the mic skills to be in the mid-card on WWE.
In reality the two companies attract two different kinds of talent. TNA has just tried to push WWE-style talent lately and done a horrible job of it.