Owning two 8 yard tanks and one box pleat, I'd argue for the 5 yard. Actually...I'd argue for a 6 yard made in the traditional style with cut pleats, stabilizer, canvas, etc....but that aside, I think the 5 yard is more practical, comfortable, and enjoyable. I have no issues wearing my 8 yard...but unless I'm going to a special affair, I always seem to reach for the lighter weight kilt for wear at games, out and about town, etc.

My next kilt that I make myself will be a reduced yardage, handsewn kilt very similar to Matt Newsome's that were recently showcased in a thread. It doesn't have all the weight and thickness of a full 8 yard tank, but the pleats still look traditional and have a similar swish, etc. That is the ultimate compromise between casual and formal in my opinion.