In reply to djwilse:
> If you have done long fell runs the actual distance and speed should not be an issue
Agreed. The main difficulty with these events is knowing how far you can get in the time allowed - you'll do better if you take it steady and get back with a few seconds to spare, than if you get carried away and are half an hour late. The only way to know this is to do a few events and see (so be prepared for a dismal failure sooner or later!).
If possible, take all your risks early on, and save a handful of controls not far from the finish so you can visit some, none, or all of them depending on time left.
Allow for getting tired - you'll go farther in the first two hours than in the second two.
Make a vague plan at the beginning. A piece of string can be useful to check your overall planned route length - once you've done a few you'll probably be able to estimate this by eye. But once you've made your plan, keep revising it depending on how fast you're going, what the terrain's like, etc. I like to make estimates of when I'll get to certain points, if I'm up on them then I'll add extra controls, more often I'm behind so miss them out.
Don't follow other people! Even on the RAB events when you know that everyone has the same control list, you could end up following someone who's lost, or who's looking for a control you've already visited, or who's super fit and disappears rapidly into the mist.