If you learn the course it becomes an easier challenge. It is hard on your feet but overall I wouldnt say it beats you up too much if you approach it correctly. Definitely a harder course than CC100 though.
I have had people tell me it is harder than a BGR purely for the extra distance and the underfoot being rougher. Others says BGR is hard as you climb more in less distance.
I did it as my first 100 and finished ok on what I would consider now to be below adequate training for it.