ArrandCee - no it would have been useless at both Boscastle and Gloucester - the Boscastle buildings wer all pitched roof so nowhere flat to land the basket and the Gloucester jobs were mianly one or two persons at a time from precarios positions (one being swept away by the river) where the only option was a winchman deployed straight to the casualty.
Sasless - the RAF don't use divers/rescue swimmers because we don't think putting another person free in the water (even if he is a God-like swimmer) is a sensible way to do things. We keep the winchman attached to the wire so he can be extricated quickly if required. In the same vein, we don't leave winchmen in the mountains cling precariously to small ledges, they only come off the wire if it is safe to do so. On decks, we prefer to deliver the winchman to the deck rather than have him swim to it and then climb up the side (lots of fun in a big sea state).
We have what we think is the best option for the variety of rescues we are called upon to perform and I don't think we have been found wanting yet - it is not that we are stuck in our ways but change for change sake is pointless.
I think the RN went the diver route because of the likelihood of needing to rescue a pilot from a ditched and possibly submerged aircraft (carrier ops) and their use of divers is more to do with Military roles than the need on a civilian rescue.
Um Lifting - good posts - put flesh on the bones of some of my thoughts.
TRC - I'm sorry you don't like the criticism - it is just my opinion that you can only make a realistic case for your basket in a very limited set of circumstances. There are lots of specialised bits of kit that would be nice to have on occasions but we start to move towards Thunderbird 2 with mission pods territory. Our role equipment is always being refined and improved but there needs to be a clear need and a demonstrated increase in effectiveness before new stuff pushes out the older (and well proven) gear.