We've had both flavors of the Glutino ones. They didn't taste much like Cheerios, though. The texture was too "airy" if that makes sense. They had more of a corn flavor to me than Cheerios. We thought they were good, but I haven't bought them again because of the expense. The texture would probably be very pleasing to a little one.
Perky o's are disgusting. Even our chickens won't eat them, and that's saying something.

The Heartland's Finest ones are OK, but I wouldn't want to eat a bowl of them. They are good in gluten-free party mix.