We recently joined one of these plans, when Obamacare made our insurance cost-prohibitive.
Since we joined, I've heard two D's affirm the choice.
Dave Ramsey said on a podcast last week that they're great, as long as you can swallow that they aren't technically insurance. There is no legal contract, but everyone with needs is getting helped.
Doug Wilson also encourages them - check from 1:10 at this link for his personal story of losing insurance because of Obamacare.
This is one reason why the midterms went the way they did.