We have had one for many years. Our kids love it. Stays up all year. Ours does have the "net wall" all the way around it so a kid can't fall off.
+1 - kids love ours which was picked up for free from a friend. We routinely face 50-75 MPH winds in NE and ours has never budged, but a few anchors wouldn't hurt. We have zero reservations with ours but also don't have any other kids using it so I've never been concerned regarding liability issues. We leave it outdoors all year, snow, ice, rain, temperature extremes have never caused any issues.