What do you guys think?

[Tobus]

Hmm...so many options.
16oz is looking more and more appealing, though.
How is the swing different with box and Kingussie pleats? I only own knife pleats.

A Kingussie style kilt is made with knife pleats. They just don't all go the same direction all the way around. They go opposite directions on each side of the kilt, meeting at a central pleat in the rear. And while a Kingussie will swish differently than a standard knife pleated kilt, you're still getting the action of knife pleats.

A low-yardage box pleat isn't going to have much swish at all. It will have some degree of "bellows" effect, but I would not call it "swish". On the other hand, though, a high-yardage box pleat will have as much swish as a knife pleat, possibly even more. Swish is a function of mass, as it moves back and forth with the swaying of your gait. The more mass you have in the pleats, the more of a pendulum effect you'll get from it as you walk. That's swish.

Just looking through my random photos, here are two showing some walking action from behind. The first pic is a low-yardage box pleat. The second is a high-yardage knife pleat. I wish I had one of my military box pleat, but sadly I don't. Anyway, even though these photos weren't necessarily taken for an "apples to apples" comparison, you can judge for yourself which one seems to have more swish...

That being said I would not have a 4 yard box pleat made from 13 oz because the pleats will not be as crisp as seen in post 13 in the thread linked below.

I wouldn't say that this is a function of using lighter weight wool. My 16-oz 4-yard box pleated kilt has that same issue if I don't regularly press the pleats. Personally, I think that is just a function of the large, wide box pleat style. The pleating style of the fabric doesn't hold itself to shape.

See, with a higher-yardage knife pleat, the deep overlapping action of the pleats tends to keep the fabric captive. The pleats aren't prone to opening up or losing their crease because the weight of all the overlapping material makes it want to stay put. And on higher-yardage box pleats (like the so-called military box pleat), you get much the same effect. The bulk of the pleats keep their crease pretty well, and the only part of a MBP that wants to lose the crease is the "rolled over" portion, and even then, it usually only wants to open up. Not bulge out in a round shape like your example. But on a wide/shallow box pleat like the one you pointed out, the fabric isn't kept in place by anything. Nothing is pressing on the creases to keep them in shape, and so they will lose the crease over time.

At least, that's been my observation.