I only have 2 kilts, one Utilikilt mocker and a USA Kilt casual. Now that I have the USAK, I've really noticed the differences in apron widths. I like how the narrow UK apron falls between my knees when I sit It took a shocked gasp from my girlfriend to remind me that I need to be cautious when sitting with a wider traditional apron.
I voted for narrow in the poll because for a contemporary kilt (ie non-tartan, with pockets) I think I'd prefer the narrow apron.