I brought my kids when they were 3 and 6. We camped at Meadow Park and liked it because it was quieter at night and the bathroom wasn't as crowded. There was also a nice place to play in the river. On the other hand, you aren't as close.
I have also camped with them on site now that they are older. On site is good because it is close and there is a lot of shade, but the music is a little later and you are camped a lot closer together.
Olson is further away, but it quiets down, there is a playground and bathroom, and a place to play in the river and you have a little more room
They all have pros and cons, but all fun places to be. It just depends on your priorities.
Pat
Listening to:
Tony Rice