We have now done more than 50 miles on this tandem, so some first impressions:-
It does what it is supposed to! Jan and I averaged over 10 mph on Sunday's ride in the very hilly North Downs - we wouldn't have managed 7mph on our old tandem. Today I rode it as a solo machine and rode 13.9 miles at more than 12 mph average. I ascended Brock Hill (renowned amongst WARTIERs as the git of a climb out of Wickford) and a reasonably fit looking roadie passed me near the bottom. I bunged it in High Assist mode and cranked it up. I didn't catch up with him, but I was gaining on him when he got to the top.
I am considering fitting lights. There is a wiring set allowing 6v lights to be powered from the main battery, but given that there is a Brompton luggage block at the front, finding somewhere suitable for the front light is going to be problematic. I'm not keen to put a permanent light on the handlebars, nor on the right fork blade. I might get some sort of fairly high-powered battery effort, but I have asked Richard of Cyclecentric for more advice. It is possible to get really good DC lights for it, and I'm thinking about Supernova, but until I have identified somewhere suitable to mount them I shall wait. Schmidt also do a DC Edelux II, without a switch. The light switch is on the control unit. Both the Supernova and the Edelux are Expensive.
There is a place for a bottle cage above the top tube, but it is exactly where I kick it when I mount the bike, so I have taken it off again. The pilot's and stoker's pedals are not directly linked in that the pilot can stop pedalling and the stoker can carry on. This has the effect of getting the pedals out of synch with one another and today I gave one of the rear pedals a serious grounding when I was going round a corner. I think we might have to link them together with bungees.*
Having said all that, I regard the above purely as teething problems which I will resolve one way or another. It's a lovely bike and we are looking forward to lots of good miles on it.
Edit: there is a trivially simple solution to the pedal strike problem. We have QR pedals! Next time I ride it as a solo, I shall just take the stoker's pedals off.