A friend of ours has used one for several years (I don't recall offhand which one, maybe medishare?). They had a few big healthcare expenses and didn't have any complaints with the system. I've looked into it a bit for us, but I have a HDHP through work and my employer pays all of my premiums and half of the family premiums so it would cost more to get in on one of these share plans. I would consider it in the future though if circumstances change.