We use Yacht Haven Quay in Plymouth. The blokes there are very helpfull and nothing is ever a problem.
I think it costs me about £2300 PA, about the same cost as a mooring at Yacht Haven. It will soon be kept in the new shed they are building, then I will be happy knowing the RIB is safe and sound out of the weather.
The only bad point I can think of is for those people that ask for the boat to be put in the water, then don't bother turning up. The staff tend to get thier own back one way or another
One more, if you have a sudden urge to go out, you may have a bit of a wait to get the boat in the water if it is busy.