Two possible variables to weigh up on the day are wind direction and strength, and low evening sun in your eyes.
Also as Dave says you might want to incorporate the so-called 'high level route' to Pillar's summit. This runs along the north side of the mountain through Green Cove and Hind Cove then up to Pillar Rock and thence to the summit. It's a magnificent walk which includes a bit of scrambling. IMO it's better for ascent than descent and that means doing the round anti-clockwise.