yup, just tried em, pretty quick.....
the annoying thing is that they're supposed to overwrite your default style....that's a no no.....
but you can get around this, import the skin as you would a normal skin, without overwriting anything....and call it something like "fast"
upload the style's folders into a new folder of your choosing, (inside your forum's images folder), and let's call it "fast" too.
then goto style manager, stylevars, and in image paths, change the path from images/ to images/fast/