Well, I've had my drive and I'm buzzing.
I drove the white one, which is a 5 seat Commercial with solid rear panels, a compass and extended electrical installation. They all look great muddy - good as I am not a willing washer of cars. They had a black 2 seat commercial and a purple Trialmaster, with a petrol engine. The Green one is another diesel 5 seat Commercial. All of them are Production trial builds, so some of the plastics will be sub-par and they are not electrically/programmed signed off, certainly the White one had a lot of random bongs while driving and some switches did not work, (including the Toot button).
It was a good drive, quiet, comfortable, controllable, lots of power. It is a heavy vehicle and no sports car, but I had no reservations about the way it went about its business; like a more sophisticated P38, with better damping. There is some roll, but likely less than my old LR110CSW and it made a lot less fuss.
Seat are comfortable; switchgear will need learning, (like heavy plant, a tank or an aircraft), the ignition key is to the left of the steering column, (old Defender flashback), my feet were happy on the floor and the rear door arrangement has been tided up. The black one had the factory winch and tow bar, both workmanlike. The rear seat folding arrangements in the commercials/Trailmaster looks a little clumsy, but I can live with it.
All in all, time well spent. The only thing I'm not crazy about is the need for a code reader/writer for the full maintenance experience; modern emission requirements make logging changes and replacements with the system compulsory. Lee, the Service/Warranty Manager for the UK, Europe and the Middle East expected a suitable system to be £600ish plus software, so not trivial but not impossible either.