I was slightly disappointed with my experience of this stone, though that was largely due to the poor light in which I saw it. It was more or less mid-day, with bright summer sunlight. This made the motifs (mostly cups, but with a couple of rings) difficult to see. They are quite worn, they do have quite a covering of lichen, so it was difficult to reconcile it with the diagram in Stan Beckinsall's book.
On the plus side, the stone is easy to find, being just to the left of the forestry track. In a better light, it should be easier to see the arkings. Given that the views are to the east, morning would probably be the best time. Evening would probably not be a good time, as immediately to the west, there is naught but hillside, so the stone would be in shadow.
(A word of warning, the whopping great trucks come belting down that track at some speed, as they aren't expecting to see anyone. The stone is on a bend, so don't be tempted to leave anything hanging about on the track, lest it get flattened)