Did this at Xmas time. We were allocated the last row, so dutifully used the rear stairs. Quite a few pax came in the wrong door and there was much "passing in the isle" as some went forward and some came to the back. I thought at the time it'd be easier boarding by rows through the front door. At least all the pax are going in the same direction when finding their seat.
Disembarking is another matter. Definitely quicker with rear stairs as well.