I joined for one year but never used it. The issues I had were they require significant planning to use. Besides planning a route to get to a "host", one has to call ahead at least 24 hours to make arrangements, just like a reservation. It is possible that a "host" will not be able to accommodate a RVer, so then the route planning is lost. Also, they strongly suggest you make a purchase from the "host" which should be in the $10 to $20 range.
I can find plenty of boondocking spots without making a reservation! And without buying something, too. Whats the point?