In reply to Chay: Like everyone else, groups or individuals, you'll just need to take your chances.
Groups from PyB and Indy use it on a regular basis but are generally scrupulous about setting a good example and communicating with and working around other climbers. Any groups of Cadets from Capel Curig should be equally accommodating but may not have local instructors.
If you are just leading routes as a pair/three you shouldn't have a great problem, but on popular venues it is always worth turning up either fairly early in the day or leave it until after lunch when groups will be winding down.
However, I would question anyone other than groups would choose that as a first choice crag. There are so many other good climbing venues in North Wales.