Totally BoatUS. Used to
work for our local office, husband still does. So, a little biased

but still.
At least here, they will give local knowledge readily, relay info for CG if you need,
radio checks... you only need the
membership for getting on-water assistance. Unlimited level
membership is the only one I would bother with. The $150 doesn't get you much.
But you should check out the coverage range and access for your local provider before you decide, get some local reviews/opinions if you can.
Don't go with anyone other than one of the big 2. We've had several around here, they manage to stay in business a few months or a year before disappearing (but we also have thorough TBUS and ST coverage; if they were the only option they might do better).