I've just got my 650 with the Sony lighted cover.
I love the reader, the light's fine but the general finish of the cover compares very unfavourably with the light wedge cover on my 505. The light wedge cover was fully leather faced, which looked very nice and made it a pleasure to hold. The 650 cover (which is also sold as a leather cover) is basically nylon (or similar) with only about two thirds of the front cover being leather faced. I'm really disappointed.
Looks like I could be joining those in the market for an alternative lighted cover.