I'm probably not really any help as never competed at Aldon at this level but have ridden round the course a few times unaffiliated (it's only down the road from me). It's a really nice course to ride. Happy to help if you have any other questions!
I've never done the CIC 1* but have ridden the Novice several times, and ridden at Gatcombe Novice too. It's a really lovely big bold and inviting XC, with 2 waters. It's hilly though, so you'll need a fit horse (more hilly than Gatcombe.) It's a fab event and one of my favourites!
I will be doing the 1* there if I don't get balloted.
I have ridden around it in the normal classes and it is one of my favourites. It is very hilly but most horses seem to manage well. I have only ever made the spring events at Aldon so not sure how the course changes in the Autumn (if it even changes at all?!) but it always seems very bold and inviting.
Again I have only ever ridden round the novice course when I was in the pony club so not much help with the fences as such but course is also local to me. The ground is usually good as their soil is sandy and drains very well. However, it can get slippery if we get a lot of rain so be prepared with lots of studs. Best of luck.