I've riden pretty much every trail centre in the UK now and the only thing missing at Gisburn like stumpyjon says is sustained decents, but thats not a criticsm at all its just the way it is. I think Gisburn is fantastic and they've cleverly used what elevation they have to create some really nice sections of singletrack that have turned out to be really technical. to get it right and clean the whole loop you have to be a confident/fit rider. No its not an all day epic but for what it is, its well worth a trip. I'm luck enough to live 30 minutes away from it and night ride there every week.
I think some comments are especially harsh as a lot of it has been made by hand with design on peoples direct input. I have the upmost respect for what they have done and should only be commended on it! 😆