I have one and it is a good product for the money. I got mine off ebay.
The good- 1. It will keep an amp from getting wet (the primary reason I got it)
2. It has a nice storage area on the top. I placed hooks up top and put a small cargo net to keep my toe strap.
3. It also keeps you fairly dry if it starts to rain, stopped of course.
The bad-1. It hangs off the side about 3 inches on both sides. It does flex when up against a tree, or whatever, but I suspect it would break in freezing temps, which I have yet to try.
I will try to locate you a picture.