Basic notions:
Neither possingk nor myself are exactly huge folk (at least from his pic).
The sett measurement is unknown until one or the other GETS the material.

The issue is between a 5/6 yarder and 8. THAT is a big difference of about 3/4 yards in back verses 6 or so. A few inches in sett difference will not make THAT HUGE of a difference. Anyways, a sett can could be manipulated either way by striping, cheating, or other manipulation of the layout.

What is at question is the heat level of a 16oz kilt in either smaller (5-6 yards) or "full size" (8-9 yards). What we are wondering is the practical matters.

My question:
Primarily, how much VISUAL and TEMP difference is there between a 6 and 8 heavyweight? Is it primarily a pleat number issue or a depth (in general as we have NO numbers for this sett).
My second kilt is so I can have a more "swinging" kilt for parades, etc. For formality, a 4 yard box pleat is perfect as is (which I am making regardless).
How much different is the look/swing of a heavyweight 6 and 8?
(Now is a good time for Hamish to offer an opinion based on his supplies and experience)

If possingk is after something else, I'll let him speak for himself.