I'm an ACE owner and while I was at the dealership getting my coach ready for my trip to Arizona I took one our these out for a a test drive at Total RV. Let me tell you that coach can get up and move, there is plenty of horse power to spare. I will caution you the brakes are excellent. It had great road manners and pulling through the narrow lot at the dealership the turning radius was impressive. I really have nothing but good things to say, but I was satisfying my own curiosity. I first got a look at this diesel pusher down at the Tampa Show.
As for the low profile chassis, I didn't even think about it. I guess it's a good trade off for parking it my the barn...(being under 12')
I remember the living seating space was real good, the even space around the bed was nice, even with the pop-out in. The cargo bay was massive, shower was huge, my wife really liked the wet storage by the entry. Overall I was impressed especially when you see the price an think "Cheap Motorhomes".
I would expect since the Palazzo is a small diesel motorhome with an engine that does not break a sweat that it should be fuel efficient.
I did find a really nice and detailed walk around review of the Palazzo with virtual tours:
2013 Palazzo Small Class A Rear Diesel Pusher Motorhome http://blog.thormotorcoach.com/finally-an-affordable-rear-diesel-class-a-motorhome/
I wish you luck.