I've only had this cover for two weeks but it seems to work quite well. The cover is a little bulky, about 3/4" thick, it makes the Kindle the size of a normal paperback book. The kindle fits snugly in the case and can be a pain to take out, a butter knife will pop it out with no damage. When I got the case I fully charged it with my USB cable like the directions stated and that has been the last time the cords been used. I live in Las Vegas so we have plentiful sunshine. I put the Kindle in the window sill when I go to work and that's all the sunshine it gets. It did take about 3 days worth of charging to get back to a full charge after I drained the cover battery to below 30%. But I was using it a lot during that time. The only thing I had to be careful about was that if it was in the window sill with the window closed the cover got pretty hot. I remedied that by cracking the window open so some cool air blew on the case. Their are only two couple of things I'd change about the cover.
1) I would like to be able to dim the reading light. I have a 2 week old daughter and when I'm rocking her to sleep at night the light it pretty powerful, i put a piece of scotch tape over it to dim it.
2) To tell the cover battery charge level the cover LED light goes from Green-Orange-Red. Orange and red look a little to much alike, at a glance you might think it one was the other. A charge indicator that was a little more precise would be nice. Whether it was a LCD screen with a percentage or maybe bars like on your cell phone signal strength. The orange covers 30%-80% charge level, so mine is usually always orange.
I bought this cover because I'm in the military and go places where electricity isn't always reliable. It will never lower your power bill enough to pay for itself, but it's nice to be able to put one power cord in a drawer and forget about it. If I had to do it all over again, I'd still buy this cover. I like it.