Tuolumne River rafting trip

[TigerFan]

We're considering a 2-day rafting trip on the Tuolumne River. I realize that it's technically outside of the park but I'm hoping someone who has done this trip can give me some info about their experience. I can't seem to find much in the way of reviews, forum posts, etc.

My biggest concern is water level in late July. I know that the Tuolumne flow is dam controlled but the outfitter I spoke to seemed a little too vague about what kind of flow to expect. And she was totally unconcerned about taking my son who will be under their minimum age -- unusual for a river advertised as class IV...

Any insight out there? (I'll even take hearsay!)