In reply to Removed User:
I did a pb at Glen Clova a couple of years ago - first time under 90 minutes, so I have quite good memories of the race. The first half, down the glen, is more undulating than hilly, but there are some sizable undulations. I do remember driving up the glen to the start thinking it was too lumpy for a fast time, but it turned out I was wrong about that. The second half, back up the glen, is fairly flat, but there is a bit of a sting in the tail towards the end - nothing too severe, but a bit of a slope just when you'd like it nice and flat.
It's very weather dependent - I've been lucky the two times I've done it, with decent weather and not too much wind, but friends have done it in blizzard conditions with serious headwinds.
As for doing two halfs in a week - you'll be fine. You obviously won't gain or lose any fitness between now and then, so all you can do is get loose and try to get the legs feeling as fresh as they can, It's a nice race - I'm sure you'll enjoy it.