Hilly and rocky. Not being trite but that's what the Dark Peak is with some peat type bogs thrown in if it rains a bit before the day.
I'd say that anybody who rides a few times per week could make their way around 23 mile Peak route. Even if you went for the bigger ride and bailed, it's easy enough to find your way back to Edale although there may be a hill of fair distinction in between you and the car park.
I'm reading between the lines and I reckon the intermediate route could be out of Edale to Jacobs Ladder. Then South Head to Roych Clough, round to Mam Nick and then across to Dirtlow Rake and Pindale then Roman Road to Hope Cross with Jaggers Clough back to Edale.
If that's the case, then my money is on the hard route doing the same with a descent from Hope Cross to the A57, across the road and over to Lockerbrook, Fairholmes and up to Whinstone Lee Tor. Then across Yorkshire Bridge and back to Hope Cross and then down to Edale via Jaggers.
I'm not sure on the mileage though, I suspect it would be more than they say it is so maybe I'm typing out of my arse?