A personal opinion resulting from a side by side comparison of 13oz Scottish Wool, 12oz Poly/Rayon, and what is listed as 13oz Acrylic.

Wool -
The feel or "Hand" of the fabric - Hard twisted Worsted Wool results in a firm, slightly knubbly feel to the surface of the fabric. The ends of the wool "hairs" is minimized and give a non-itchy feel. The weave by Lochcarron is has a few more of these nap "hairs" than does the weave by Marton Mills.

Wrinkling and care - Wool is the Standard Kilt fiber. It wrinkles very little and a shot of steam will allow wrinkles to fall out quickly. Too much steam though and you may steam out the creases requiring basting and re-pressing.
Wool requires hand washing and will take a while to dry.

Overall effect - The "Swish" factor of Wool is the best of all samples.



P/V -
The feel or "Hand" of the fabric -The Polyester/Viscos (Rayon) woven by Marton Mills results in a very smooth, almost silky finish to the fabric. The individual yarns in the weave appear finer to the eye. To me the P/V is "velvety".
The fabric used by Sport Kilts while listed as P/V feels more like Cotton flannel. It wrinkles far more, and I suspect is actually more like a Poly/Cotton.

Wrinkling and care - True P/V resists wrinkles the best of all that I have tried. Creases, when properly set, are virtually permanent. I have yet to need to baste and re-press.
True P/V is machine washable and dryable. Dirt will not stick to it.

Overall effect - The P/V feels light when you first feel it but the Swish is comparable to Wool.



Acrylic -
The feel or "Hand" of the fabric -The fabric used in a Stillwater Kilt feels to me to be similar to Polar Fleece. The surface has quite a bit of "Nap" or fuzz. The individual yarns are very large and the weave is the loosest of all the samples.
I find the Acrylic to be the least Wool like which is strange as Acrylic, if Worsted and hard twisted, has the potential to be the most Wool like.
The fabric used by Frugal Corner and The Gold Bros. also has the fuzzy nap but slightly less than the Stillwater fabric.

Wrinkling and care - Both wrinkle and pill quite a lot. The creases will fall out after a while and need basting and re-pressing.
After machine washing some ironing will be necessary.
I find pilling to be a major problem with the Acrylics.

Overall effect - Although listed as 13oz or heavy-weight it actually weighs only 5-6oz per fabric yard when I weigh it on a scale, which to me feels very light and fly-away. The least "Swish" of the three.

Please remember that this comparison is purely my personal opinion.