I have the Scarabeo 500.
Regarding the styling......I do not like the look of most modern maxi's. In fact I quite strongly dislike the look of most o them. I much prefer a scooter that is unashamedly a scooter. I love the look of vespas, but do not like some of the drawbacks that come with them. I like the bigger wheels the better storage and the more powerful motor that vespa does not currently match in any of it's models. So my thinking is very much like yours. The scarab is one of the only maxi's that is retro styled.
I get about 300km to 11litres of fuel.
My riding is a mix of freeway, local riding, and some less fequent long distance riding. I love that the bigger motor gives me the ability to accelerate strongly at freeway speeds.
I use the scarab as my primary transport, and with the 53 litre box on the back I have so much space. I have the bigger aprilia windscreen and the J costa variator, both of which I would strongly recommend.
Regarding downsides, my friends think that it is a bit too heay for some situations, but I dont find that a problem. I am just used to it I guess. Also the riding position is much more like a vespa that a maxi. This is good and bad of course. I am fairly tall and have not found a more traditionaly shaped maxi that will fit my knees yet (tried gilera, piaggio, peugeot maxi's). It is also a good scooter for pillions too, has a nice long seat for them.
As you can probably tell, I am very positive about mine, and have yet to see another scooter that I would swap mine for, even though I am regularly in scoot shops. Overall a strong recommend from the 6000km I have so far covered.
Scarabeo 500ie.