Going by the design and quality of build of my azub tricon gr a two wheel recumbent built by them seems a good option
Indeed. Though I'm sure a Scorpion would fare equally well on build quality, you'd go about half the speed on one on account of HPVelotchnik's general inability to keep the weight down.
IIRC Woollypigs OTP has a Six, and is very happy with it. What puts me off (apart from the handlebar position and general familiarity with the foibles of Streetmachines) is that none of the UK AZUB dealers seem to carry demo models of the bikes, and my ability to get a foot down is marginal enough that I'm disinclined to buy one without having had a proper fiddle with the seat/bars adjustment and test ride.
I also think the HPVelotechnik luggage racks are substantially less fugly (I'm unlikely to ever need the ability to carry six panniers), I prefer the simplicity of direct steering and - until someone
[1] works out how to drive an E-14 actuator without an electric assist system - their custom Rohloff shifter seems to be the least worst option
[2] (though I could probably obtain it as a spare part if necessary).
[1] Preferably not me, unless someone wants to donate a suitably equipped e-bike for reverse-engineering purposes
[2] I detest grip shifters, but you can't drive a Roholff with a bar-end, and trigger shifters via a widget aren't ideal with USS.