We have also recently returned from a 2,100 mile trip round the west and east coast of Scotland. The best I got was 34 mpg (roof up, wet run up the M6) and the worst 24 mpg and an overall average 29 mpg over the whole trip. Pretty pleased with that as the "usual" is 23 mpg.
Only E10 for me, as I'm too tight to go for Super. I figure the engine's out of BMW's tractor anyway, so probably designed to run on rubbish

Fabulous empty roads and as you say Tim, fuel around the same price as at home.