It moves around some when you're trying to take off the tank.
I picked up a brand new NXe tank off of eBay for 5 bucks. Man was I impressed. This is a great cover. It fits over the tank perfectly and has a nice grip/butt stock thing on the back so it will fit perfectly on your shoulder. The zipper seems to be heavy duty. It does move around some when you try to take off the tank, so it may need some grips on the inside.
Nice cover, I would suggest that NXe puts grips on the inside of the cover for easier tank removal.