My "gentle" might not be the same as yours. This was a steady 75 mph cruise whist on the motorway and as fast as possible allowing for traffic with 3 people and 3 bikes and a weekends worth of camping gear from Dalbettie to Rochdale. I had about the same from a trip at 60-70 mph from Leeds to Fleet and then at 80-110 from there to Southampton. I could probably get 40mpg out of it if I sat at 60mpg but I find it far to boring and it does late 20's at 90 so it's not worth the hassle.
I'd personally rather have something light but it's useful being able to fit people and bikes inside the car and it's not that heavy for it's size, about 1400kg or about the same as a new Focus.