I held back my son. Best decision I ever made. Giving him that advantage has already paid off huge and I'm sure it will continue to do so. Just saying...
what's the upside of him playing vs younger kids besides improved confidence?
I'll retort with what's the downside? There isn't any downside. So why wouldn't I take it? I get why it would be damaging to kid socially and developmentally if we reclassed him in middle school or just prior to high school. I'm not talking about that though. We did it early before any of that is a factor.
Starting a kid late in school is one thing, holding back after they have already started school is a whole different thing. Hugely different social ramifications.