Originally Posted by
Piipp:
“I always took it that he reset because he had reached the end of his regeneration cycle and his body was resetting for the new one; I always accepted this as a valid reason for his body reverting back to the original version of youth; clearly the Doctor doesn't always reset as the first regenerated because of his body wearing out but he didn't revert to a younger looking self; this is because he had another regeneration waiting in the cycle; Eleven didn't and so the new cycle reset his body before it began to alter it. That's the way I took it anyway and it washes with me. (I know One didn't regenerate strictly because of his age but it's almost the same and it's the easiest way to accept Eleven's reversion)
EDIT: Thinking about it Hurt's Doctor actually DID regenerate because his body aged too much and he didn't revert to a younger version. So yes, it's because of the new cycle and that's what I'm sticking to.
”
What your saying is basically what I think you are supposed to think as to why it happened in-verse, but all I'm saying is that in the real world I feel that the only reason that the reset was written in at all is because Moffat had to write a quick way out of the aged appearance because for some reason he couldn't bare to see him change as the older version. I don't think there would have been any mention of anything like a new regeneration cycle reset if Matt hadn't been aged beforehand.
Personally, for me it made the whole thing feel disjointed. One minute he's seemingly regenerating in spectacular style on the clock tower while managing to stick it to the daleks at the same time, then the next, hes back to normal in the TARDIS to say a few words, then have the quickest, most undramatic, blink-and-you-miss-it change he has ever had.
Had Moffat not been bothered about some apparent need to put him back to normal for the change, and had just let the whole regeneration go through on the clock tower, it would have possibly been the coolest regeneration the Doctor had ever had - The doctor, defiant at the end, killing Daleks to his current body's last breath. With the nonsense of the reset though, the whole thing lost all the momentum it built up, and the actual change just seemed like they'd ran out of budget for regeneration effects after using them on the clock tower.