I have a semi-trad that I wore through Oklahoma's heat - 110° (not too much humidity though). It's as cool as you're going to get in hot weather, but the wind will certainly get ahold of it. I don't own a wool kilt (yet) for comparison, but both of my UtiliKilts stay put much better in a breeze.
I give the Semi-trad and Casual the most use. They clean up easily after a spill at work or out to eat. The Semi-trad dresses up as easily as the Premiere, although the Casual does fine for the office with a shirt and tie. One consideration is that the tartan choices are limited in PV. However, I still have a dozen or so on my "PV would-like list". I wear the wool Premiere in the family tartan about 1/4 of the time. Happy kilt hunting! That is a large part of the fun!
Forum Rules