90% of the time I use Tesco, never had any problems in 8 yrs of running Scoobs....... When I use V Power I get around 22-23mpg, but with Tesco it's 23-24 on the same runs, but then my car was mapped using Tesco's so it should be more optimised for that fuel...
Depends what's available in your area. not everone can get both kinds...