I have the Mizar G Living which we bought last February. All has been relatively well apart fom a few niggles. I have been through the whole van and tightened everything up as all appeared to be a bit loose - probably just wearing in.
I too have the step water problem but solved this by (wait for it) duck taping the vent shut - stops the cold draught too!
Have noticed the water collecting on the roof - will watch the sealant!
I had a decal missing above the gas locker door which I ordered through the dealer on FEBRUARY 14th and am still waiting! I also ordered a new table as it had delaminated just above the screw which tightens it up back in August and am still waiting for that too - they are extremely slow aren't they?!
I had an extra battery fitted and wanted another cradle fitted but at apparently £800 didn't bother! I changed the original 85Amp for a 110 and it will fit in the cradle but will not wind up as far as it should. I have secured and blocked it from coming back down by severely tightening the stop screws against the sides and all has been fine. (If you do this make sure you cover the +ve terminal as it will short out on the chassis otherwise) The dealer then managed to fit the 85A under the offside rear seat and all is now well with power. The cradle thing is a stupid idea they would have been better off putting it in the garage or something.
I find that the gas strut on the door is too weak - almost no resistance at all. At the weekend the wind took the door and it cracked the exterior trim behind the bottom hinge when it collided - apparently these stuts are all weak and will be on the lookout either for a regas or different strut - be careful of yours especially when windy!!
Another problem was water appearing from under the bathroom wall, turns out that the plate that the tap sits on in the shower wasn't sealed - worth checking yours as there is a great big hole under that plate!
The rear suspension creaks like crazy on bumpy roads - surely should not be like this - will attack with some grease....
Apart from these niggles have been really pleased with it - it has now done just under 14000 miles since Feb and is still in one piece...