My preference is for the 4-yard box pleat. Not all of that has to do with living in Louisiana, but I suspect that the hot weather aids my preference.
I personally think that Matt's kilts look better than the average 8-yarder in that the pleats look neater, straighter, and more in line. I think you see more color in the box pleats than in the knife pleats. Also, the issue with the swing for me is that I prefer less swing because I'm a bit of a roudy/lively Scottish Country Dancer and I would prefer to keep the secret of what's under the kilt.

The only time I ever got a school girl comment I was in a knife pleated kilt at a Catholic girls school for a Scottish Country Dance demo. I think Scheihallion is a bit out-of-line with comments of that ilk. Like it or not, the box pleat IS traditional--it's a revived tradition. Whether it's popular in Scotland or not doesn't make it any less Scottish either.