Wrinty,
The course can best be described as hilly.
Did you do the Imber 1/2M here earlier this year? If so, I think you'll find the hills much more gentle, as this route doesn't go up on to the Salisbury plain.
We do much of the route regularly in the summer in the Warminster Runing Club and I'd say it's up-hill about 1/3 of the way. I don't think it's going to be a PB route.
Andrea