We’ve done it a few times. It’s fairly tech but not silly. It’s quite stop/start and the main thing that interferes with your line is that so many of the switchbacks are tight and narrow and full of rocks, so getting around them clean ain’t easy.
There are a couple of spots that you’ll probably end up hopping off to get over/round so don’t expect to get it all “no dabs” but overall 95% ridable,
It’s a good descent, certainly a challenge. It’s on Strava as “Man Bield”
It’s only challengingly tech as far as the tarn. Below that is a (very nice) typical Lakes descent, much more open with plenty of line choices.
Route suggestion: If you’re doing it from Staveley, then after Man Bield come back up Gatescarth, over Harter Fell and then do the conventional side back into Kentmere.
(Edit: Too slow, Basically what Tomaso said)