Interesting discussion. I find it interesting that people are getting higher consumption from the 107 as well. My car was tuned on the 107 and I get very slightly better economy when I use it vs EFlex, granted I'm talking maybe 20-30ks per tank more, certainly not enough to offset the higher costs of united.
The car also feels the tiniest bit more responsive on the extremely low rpm as well with the united, like before around 2000rpm it seems smoother to take off from the lights or whatever. No idea if there is a reason for that or if its in my head.
Either way I just fill up with whatever I'm closest to when I need fuel, doesn't make much difference except price