The Ferrosi shirt is very porous, as much or more than a Supplex shirt. I noticed that the fabric on the shirt that I got from STP is 86% nylon/14% elastane. It is model 55535.
The hoodie on sale at REI is spec'd at 91% nylon/9% spandex. There is yet another on REI spec'd at (Body) 86% nylon/14% spandex/(panels) 91% nylon cordura/9%spandex and that makes me wonder if the reporting on the sale model is correct.
To add to the fray, there is a Ferrosi jacket, which OR spec's at 86% nylon, 14% spandex, stretch woven (see http://www.outdoorresearch.com/en/catalog/product/view/id/41050/category/2158/) [model 55517OR]
There are at least three Ferrosi men's hoodies listed on the OR website:
http://www.outdoorresearch.com/en/catalog/product/view/id/41051/category/2158/ [model 55531OR]86% nylon, 14% Spandex stretch woven body and hood // 91% nylon Cordura®, 9% spandex stretch woven shoulders and lower sleeves
http://www.outdoorresearch.com/en/catalog/product/view/id/25590/s/mens-ferrosi-hoody/category/2158/ [model 55530OR] 91% nylon Cordura®, 9% spandex shoulders // 86% ripstop, 14% spandex body, DWR-treated, stretch-woven
http://www.outdoorresearch.com/en/catalog/product/view/id/44043/s/mens-ferrosi-hoody-1/category/2158/[model 55530CLO]91% nylon Cordura®, 9% spandex shoulders // 86% ripstop, 14% spandex body, DWR-treated, stretch-woven
There are several women's Ferrosi models too. I'm not going there.
I've noticed similar with OR before. They crank out an amazing array of clothing. Try to ID an older OR hat. I'll bet there are a dozen variations on the Seattle Sombrero types. My understanding is that they have in-house production facilities, so they can whip up a new model on the fly. That would be so much fun to work with!