After reading about this product from another merchant, I ended up purchasing it here. I'm quite pleased.
I bought this cover for three distinct purposes, and it has thusfar served all three.
(1) RAIN PROTECTION - the Aardvark has performed well while both riding as well as during a rainstorm while on the back of my car traveling at freeway speeds. One complaint is that the water repellent layer of the saddle is not the top layer, meaning that if you leave the bike out in the rain and subsequently sit down on the seat, you're going to be sitting on a rather soggy, squishy seat. Lesson learned: wear your rain pants.
(2) SADDLE DISGUISE - while this is less quantifiable, I find that it does a pretty effective job of making my Brooks look like a crappy generic brand gel seat. Whenever I want to show off my bike, it's easy to take off.
(3) SEAT PROTECTION - The third reason I purchased this cover is because my Brooks is subject to an inordinate amount of damage as a part of my commute. I take this on Caltrain, which holds more bikes on a daily basis than any other public transportation system. As such, I had a lot of trouble with my saddle getting strafed by the brake levers of careless mountain bike owners. Ouch. So far, my Aardvark has taken a bit of a beating, but due to the cushioning, nothing has worn through to the saddle. Whew!
One complaint--I bought one for my lady's bike. The saddle is a B-17 Imperial. For some reason she seemed to scoot forward a lot on her seat when dismounting, dislodging the back of the cover. After only about a week, she'd lost the cover somewhere on the road. Designing this with some method of securing it onto the bike might be a worthwhile improvement.
All in all, if you own a Brooks or any leather saddle, you should own this cover. Period. Buy two.