No experience of Cheltenham but I had VM in Abbeydale, Gloucester and it was pretty poor at evenings and weekends. Don't forget that there's a lot of student accommodation in Cheltenham. Best bed is to Google the first bit of your post code along with Virgin Media congestion or search it on their forums.
Thanks, cant see anything much related to Cheltenham in terms of congestion. I have a few friends with virgin in the area and they all report no trouble. One mentioned that peak it dips from 200 to closer to 100 but that would still be 60 meg faster than I currently have.