Another 40-minute on-road session, with a different instructor, and I had my CBT! That was Tuesday. So on Wednesday, I went into the Honda Motorcycle showroom and ordered a SH125 - pearl white, to match my teeth.
Having placed the order, I was relieved to read gizmo's comments about twist-n-go scooters ^
I could have taken delivery on Thursday of next week, but I'm off cycling in the Yorkshire Dales for a few days, so have agreed on Monday 21st for delivery. Yes, much better deal than Vectrix - £2400. If it does 100mpg, which is not unlikely, the petrol costs will be about 6p/mile. At 5000 miles per annum, that would be £300 worth of petrol. So like you guys said, on a cost basis, the Honda wins hands down.
I'd like to take the bike test, rather than riding around with L plates and doing the CBT every two years. I discussed this with my CBT instructor, and he advised taking the test on a bike with gears just to make me "futureproof".
By the way, when I rode the scooter on Tuesday, it had quite a bit of fresh damage on it that wasn't there on Friday. Turns out that a student screwed up the emergency stop - on his test!