So far I have:
PV is machine washable. Are PV kilts really "throw in the washer"?
PV is cooler, but that is not really a factor here in the land of no humidity and temperatures that do not rise above 90F.
PV is easier to spot clean. Although I have read with interest that some tartan material is teflon coated? Can/should wool be teflon coated?
Wool allergies. Thankfully I am not yet allergic to wool.
And finally, "Stick with wool"!
If I could throw a PV in the washer without having it ruin the pleats, that would be a real plus.Also a real plus would be virtual imperviousness to stains. Because I cook a lot of breakfasts the concept of having my kilt be spattered with bacon grease is close to horrifying. I am also considering the possibilty of ordering a WW1 reenactors kilt apron for just such tasks.

Any other thoughts, ideas, or suggestions?