Great message Mary, that really deals with the issue well. I do know people who have an eight yard kilt but don't wear it often because it's so hot, especially in the summer. The Highlands of Scotland as not as temperate as some of our areas in the US. Up in the mountains, it's nice though. So the casual may be more suitable for those in a warmer clime, or maybe the 8-yard in the 16 ounce. I always laugh about this because people ask me if I'm not cold in a kilt. It's actually a very warm garment.
And Aiden, it's not an issue of "coverage" that decides between an 8-yard or a casual kilt, it's usage. The 8-yard will be hand sewn with correct pleating, etc., whereas the casual one may have wider pleats and not "swing" the same way, as Mary says. If you want a kilt to wear to formal events, especially if there are real Scottish people there who know the difference, then you definitely want the 8-yard. Wearing a casual kilt to such an event would be like wearing a tee-shirt with a tuxedo printed on it to a black-tie event.
On the other hand, it you're mostly wearing it to festivals and such, the casual kilt is perfectly adequate. Just make sure it's a good quality worsted wool and made by a kiltmaker, not a seamstress. Kiltmaking is a very specialized art and even the best seamstress may not understand the issues involved.
While we're on the subject Mary, I do have a question. When I was measured for my Thompson kilt, the fellow asked if I wanted the "traditional" measurement, or to be measured where my pants ride. Wanting to be as traditional as possible, I chose that one, but I sometimes regret it now. The reason is, I have more belly than I really need, and since the traditional measurement puts the belt at the belly button, my kilt should be worn quite a bit higher than I usually wear my pants. I find that quite uncomfortable and the kilt tends to ride down to my actual waist, rather than the middle of the belly waist defined by traditional kilties.
Is the lower waistline considered gauche or uncouth at all? I have seen large bellied men with their kilts up in the proper place, but I just find it very incomfortable and hard to breathe with the belt around my middle, rather than just over my hips. Just wondered.