I have a Moto Guzzi Nevada 750 that can run 80 all day & never miss a beat. In fact, thats all of 2 MPH faster than the thing was allowed to run as it broke in. 5,000 rpm translates to 78 mph on the speedo. It will get over 100 easy enough, but 110 is about it. The Navada has a small tank & will need gas at about 110 miles. Thats when it starts flashing the little "Gas Pump" light. It will deliver mid 50's MPG around town, easy running, start running over 90 & the MPG tanks, low 40's. Running 75 & 80, low 50's, upper 40's .Shaft drive, no chain hassles or belt squealing. There is a different model, the Breva, has a larger tank & different seat, otherwise the same, no,thers another difference. , tubeless tires on the Breva.
Also, the Suzuki 650 Savage with the chain mod will run higher speeds & deliver decent MPG, but ask Hutch, cuz he did the mod, I have one too, but its still belt drive.
I am just not comfortable with heavy bikes & I have some kinda hangup on wanting god MPG out of a bike, others who can ride bigger bikes or haul passengers, well,, I just wish I felt like I could do that, But I am plenty happy with the bikes I have found that I can man handle. The MPG & looks of the RE are why I am wanting one, that & it's small enough I can pick it up if I drop it.