I also bought the performance products version. The "high level" of outdoor cover, storm proof I believe. I bought it last December and have been pretty happy, I have flares and they make a custom fit for that.
HOWEVER! The pattern does NOT have mirror pockets, so I have to fold my mirrors everytime. Also, with 916 fiberglass bumpers (which probably are the cause) the cover does not stay on very well in high winds. So I use a 4 foot bungee cord on the security cable loops to hold it on.
Does a great job of keeping water, snow, leaves off the paint, and seems to breath very well.
If it lasts, well worth the almost $300!
The 914 is happily topless & coverless in the 50 degree sun right now though