DS8 has been entered early, though with a fall birthday, so he is currently the youngest in his third grade classroom only by weeks. The psych who tested him has recommended a second acceleration into fourth or, alternatively, have him skip fourth and enter fifth grade (first grade of middle school and first congregated gifted classroom) next year. He is tall for his age and has good fine motor skills but is anxious and socially awkward. So, we're of two minds, just like you.
He has been allowed to take part in fourth grade math class since after Halloween vac, the school psych (who does not know him yet) is scheduled to observe him next week and we will have the big conference about how to proceed before Christmas.