I'm in again for the 70....Will be my 3rd Grimsthorpe ultra. 
If dry, the terrain is a bit easier than Thunder Run, (did it solo this year) but if wet like this year, it's a bit swampy in places. 
But always good no matter what the weather. My fave race of all time. 
The 10 mile loops don't get boring for me, & it's nice running at night. The lake looks amazing if there's a full moon to shine on it, & the castle all lit up at night is emotional!! 