I love this run. I do most of the 10 as my marathon training, digressing into the middle of Bentley and then picking the run up again at Mill Farm in Isington.
It is definitely not flat but the scenery is stunning. After 'that long drag' up to the top at Binstead, you get a quick steep short downhill to Blacknest, then it is pretty much flat until Isington when it undulates most of the way home. The view over to Froyle on about mile 7-8 is brilliant.
Do the run, you won't regret it!