2 straps or 3 weigh in men! (and women)

[M. A. C. Newsome]

A two strap kilt is easier to get on and off if you have mobility limitations, otherwise I'd say go for three straps which looks much more traditional.

But that's just it. People tend to think they are "traditional" because it's the norm these days, and it is what people are used to seeing on a kilt. But really, the stronger tradition is to not have a lower hip strap. Most people just don't realize it's an option.