Well, they vary state by state and school by school. Some are fabulous. Some are terrible. A lot of them are somewhere in between, and not every school is a good fit for every child.
All that said, I think one thing that can be an issue with a new charter is turnover in both teaching staff and administration. But I'm not sure that isn't an issue everywhere. Another possible issue is resources and things like transportation. Again, this depends on the school and the system.