As said that BM route is a vague vague track, but if your into that stuff, dont mind having the map in your hand all day, a bit of pushing and the chance of a few wrong turns it really is worth a visit.
Once your up on the plateau and a few miles into the distance it does have a fantastic wilderness feel, I’ve wild camped up there a few times and it’s probably one of my favorite spots in Wales to do that, you’ll barely see anyone all day, I think the first time I went up a just saw a couple of squadies on maneuvers…
If I was going I’d just to an out and back, keep an eye on things and leave a lot of daylight incase anything went wrong. The first time I rode it I did an out and back but came back along a long dissapeared BW, it was a 7hr ride and I’d only took a twix!
The alternative MM route is a classic, plus if your in the area the Doelthie’s probably worth a shot?