Right, done about 150 miles so far in mine.
First thought - it's a bit slower than the Twinair 500/Panda 4x2.
I guess this is down to the extra losses through the transmission, and for most people its not a problem. It is still more than adequate, and drives well, but if you come out of a Twinair you will notice the difference. That said, the engine has only done a couple of hundred miles, so will loosen up.
Handling wise, on road is pretty good, touch more noise off the tyres but to be expected, and on greasy surfaces the M&S tyres (Continental Cross Contacts), do feel a little less surefooted. The ride comfort is very good, compliant over bumps and comfortable. Body roll is much the same as the normal Panda, which is impressive considering the extra height. Traction is good, even dumping the clutch to spin the tyres blinks the ESC light a couple of times, it sorts things out and off you go.
Off road - I've only had the opportunity to go down a small track, which does get very claggy usually. Unfortunately, at the time it was about minus 3, and was like driving on concrete, didn't slip a wheel once. I'll try again when it's a bit warmer and gloopier.
Inside, I like the leather patches on the seats and door cards, should be much harder wearing. The metallic finish on the dash and wheel is nice, but feels a bit rough. The main improvement is the centre console, which brings the cup holder, 12v Socket and Blue&Me socket higher up, offering a hidey hole below, which I prefer.
Fuel economy at the moment is awful (comparitively, its averaging 38mpg according to the trip), but thats all in full power mode and not driving economically. I'll try to get more economy once it's run in a little more.
All in all, it's very good. I'll report back when I've done a few more miles and let you know how its going.