The two stroke scooters get about 75 MPG. The Harleys get about 42 MPG. My V-Strom gets 45.
Based on my own experience and that of other scooterists whom I know personally, the most reliable machines on the market right now are from Yamaha and Kymco. My Vino 125 has over 40,000 miles on it and has never stranded me, parts are cheap and the design is simple enough for DIY maintenance. The Suzuki owners in my circle are also very happy but they don’t sell anything smaller than a 400cc in North America. Piaggio (including Vespa, Derbi and Aprilia) make good-quality machines but parts & service cost a fortune.
By far the best feature of scooters IMO is the amount of storage space. I can fit a week’s worth of groceries under the seat, and with my Givi case I can carry enough for a camping weekend.
The two stroke scooters get about 75 MPG. The Harleys get about 42 MPG. My V-Strom gets 45.