I personally prefer box pleats. No scientific reason other than I think I look better in them. I really enjoy making kilts - box pleated as well as knife pleated - but just feel more comfortable when I wear a box. I'm new to being kilted but love wearing a kilt and HATE having to put on pants when decorum requires it. Choosing a box vs knife pleat is kinda like choosing between a single or double breasted suit coat - in the end it what feels good on you.