We have used both MDL at Hamble point and HYS at Port Hamble.
Both very good. MDL is cleaner and smarter but HYS are just as competent!
theres not much in it and the extra run down the river from HYS gives you opportunity to
a) warm the engine up before you get to the unrestricted area and
b) get shouted at by all the little sailing boats who think they own the river and its appropriate to stick in a tack for no reason when they are 6 feet infront of you on a busy sunday afternoon when everyone is coming back in the river!!!