Just seen this thread now after a while offline when I saw Pembrokeshire flag up
Twin jets are very good. I'd never had any jet experience before work took on a twin jet landing craft last year, but after having used the voith schneider system on board the tug, jets just seem almost the same, infinately variable control in any direction with incredible accuracy.
We have twin ultrajet 305's with a joystick for clever control when you don't want to use manual bucket/steering wheel controls. Spent a couple of days last week on the boat at work putting people on and off a pole just off st anns head and then holding about a metre off the same pole in the swell for over an hour while things were sent up and taken down from the top. With the 1.3knot current broad side on, I am not sure many other boats would have been capable of that in the same size class.
There has been much interest when we go up to haverfordwest with people regularly asking as we berth "how do you do that" and "I can't get my boat to do that". I generally tell people to look for venturejet on youtube to see more