It is hard to comment without understanding more about his social delays, the only thing you have mentioned so far is that he has difficulties waiting for others to finish, which sounds perfectly age appropriate for a 6 year old who isn't challenged by his work.
DS, just turned 8, was very slow at developing age appropriate social skills. He simply couldn't relate to kids his own age and could not play, just talk and build,preferably with grownups or kids much older. Having two more I can tell, in retrospect, that yes, those were social delays. He has mostly outgrown those, and now is quirky and socially awkward but does well being mildly accelerated in third grade (birthday only weeks after the cutoff) - it's not great, but he's okay, and doing much better than he did with his year in preschool and k. He also has a friend in fourth grade in another school which he does great with playing one on one - eccentric but easy going and a girl, all of which helps. His test scores would warrant another acceleration but we are taking it slowly, and have asked only for math acceleration into fourth so far. A full skip into fourth would simply be hard, for many reasons, not just to do with his personality. Gifted track starts in fifth but will involve a major commute into a middle school on the other side of town, and it's tough starting middle school at age eight, if only because of the organizational demands. On the other hand, I if we decide against the full graded skip we have some serious tweaking to do for him to survive fourth grade.
Like others have said, it is rarely possible to find the perfect placement for very asynchronous kids. There is always some trade off, and sometimes you just have to try things out.

Last edited by Tigerle; 10/25/14 04:40 AM.