Alan,
have done Roych Clough a few times, and you’re right, it is a great trail. I did it on a 90mm full suss (my trusty 2002 Stumpjumper), and I have to say, on Rooley Moor I was congratulating myself on not bringing my hardtail – I am short enough already and don’t need any more help with a compressed spine! A hardtail 29er with bouncy tyres is probably optimum, but I haven’t got one!
I think the hardest section was the bits before the MTL – I was seriously considering my sanity for those bits. Would be good to hook up if I do decide to go for a double attempt, but as you say, a 200mile ride off road is a different consideration to 100miles. Maybe next year….. Not sure if I would fancy the thought of doing some of that at night, and you are very much on your own (which is great until mechanicals or worse happen).