We have a Chi and I have two young kids. Althoug he's still a puppy and still very hyper, we don't have a problem with him. We did a little bit at first, especially when he was teething and he would chew on anything and everything, but a friend of ours is a dog trainer and she took him for a couple of weeks and straightened him out. I'm assured, though, that once he gets over a year old he'll calm down a lot. He's still insanely hyper, but that's what makes it fun for the kids to play with. His mommy (she belongs to my best friend) is the complete oppisit of him...it's hard to believe they're even related. She's so lazy she won't even jump in your lap...she'll just sit there and look up at you with those eyes untill you pick her up and put her on your lap yourself. So I guess every Chi is different.
We've also had cockers and I would reccomend one of those too. They love to play...they LIVE to play. They are so much fun to be around, but I would consider a cocker more of a medium dog.