I wear my SWK Nylon Sporran with all my kilts for several reasons. 1) It keeps all my stuff in one place. When I wore pants, they all had 4 pockets and I had a routine for where I kept stuff. My kilts are all different and I tend to forget where I put my checkbook or wallet due to changing pocket configuration. 2) The sporran readily identifies my kilt as a kilt. It completes a kilted outfit. 3) I'm used to wearing a belt pack (fanny) out for the same reason, so it was a natural progression.

While home or at the homes of friends or family, I will take off the sporran. Wear it or not, it's a choice I make for convenience or comfort, rather like my choice of kilts for below the waist apparel. I do it for me, not someone else.

Semi-formal or formal is a whole different matter and I defer to the experience I've gained at Xmarks and the traditionalists (thanks Hamish).

Dale