From the outside he seems accurate enough, but as an Aspie I can assure you there's all sorts of problems.
1. He is extremely self-centered. He does what he wants to do,
never considering those around him. A true Aspie, however, does care. Most of us really want a social life, acceptance, we just don't know how to obtain it, and shy away out of fear. End result is similar behavior, but the thought processes that lead to it are vastly different.
2. He is ignorant of the obvious. Example: there was a Christmas episode, and he wasn't aware that gift-giving is a "non-optional social convention." Even someone without proper social skills could figure this out based on the fact that virtually everybody does it at scheduled interviews. In the same episode, he fails to acknowledge it as Christmas because Christ wasn't born in December, completely ignoring the possibility that the celebration of Christ's birth doesn't have to fall on the same day as His birth actually occurred. Furthermore, he claims that December 25 is Saturnalia, which is
grossly inaccurate, and shows a complete lack of research. No nerd or Aspie would fail this hard.
3. He plays Age of Conan. Nerds who play MMORPGs tend to play LoTRO or WoW. Age of Conan has a comparatively lousy mythology and shallow gameplay.
For the most part, the only people who think he's even reasonably accurate are not nerds themselves, and are certainly not Aspies, and wouldn't know accurate if it bit them in the butt. If you want to see a real Aspie, watch the movie
Adam. But more importantly than that, all the characters are complete jerks, even Leonard (who is supposed to be likable). Even if they were realistic, the show is just unpleasant to watch.
And for the record, nobody has compared me to Sheldon before. I have, however, been told that if I was a serial killer I would be Dexter.