After doing the big 3 (not that they need to be completed first, it's probably a normal progression), its definitely a step up in terms of a challenge. I think the reasons it doesn't get many attempts are 3 fold
1) it's a long way to travel for most, 2) it's seriously tough terrain which doesn't appeal to some, especially when Snowdonia NP is so close with its "easier ground", 3) taking it on when the veg has grown adds to its difficulty, which is most of the year after April. Oh and it's a relentlessly tough round that takes a lot of recceing. I am still tempted though
..... Maybe next spring.