I've tried all four, and for some reason kind of prefer the Gutterball. It feels really fast and responsive. I've test ridden it a couple of times now. Also, it seems easy to maneuver. I feel like I can go down steep hills and make quick turns on it.
This is what matters. If you don't feel 100% sure yet, keep riding whatever you can find, but ultimately it's you who has to/gets to ride it.