I've switched back to normal Tesco. I used to run momentum all the time and my car runs better on it and I get better MPG.
However, the price rise in fuel means i've had to come off the good stuff.
i'm sure someone on here did a test not that long ago on value for money with regards to normal fuel and high octane stuff,yes high octane stuff is more expensive but he got better mpg from the high octane stuff and after a months test on both i'm sure he said the high octane was more beneficial