My husband and I just started coaching three weeks ago. I have to say so far, I'm pretty sure my husband has gotten more out of it than the kids! It's been a very enriching experience for him and he looks forward to the meetings. I'm around kids all the time so it's not as delightful for me but I'm still enjoying it!
My son's team is a mixed grade 3rd-5th team. We chose the kids and made it half boys and girls and mixed the grades on purpose. We didn't want kids messing around in the garage- we wanted to work on Odyssey!
So far it's going very well. Most importantly, I'd say that my son and a girl who is also HG+ on the team, are learning to respect others' ideas, listen to what they have to say and to wait their turn. That sounds a little bit immature but when you fill a room with 7-10 year olds and ask them a question, it's loud, silly and chaotic while they make their case for their idea. Learning to work as a team, not boss a team around is the best learning experience for both my son and the other girl!