Figuring one person in one thousand will have a serious problem with any electronic device, let me put myself squarely in the 999 camp.
I consider my PRS600 to be a well designed and constructed unit. It feels very solid and looks great. I don't think the Collections feature gets enough good press. Before I got mine, I really wanted Folders. Now I prefer Collections. Only one copy of the book, and it can be in Novels, Science Fiction, and any other appropriate category. I use Calibre to manage my EBooks, and it works wonderfully. I do have the PC based Sony reader software turned off, since I handle downloads with Calibre. I only charge my unit with USB (Not Sony recommended - hah!). Battery life is great - connecting to download news seems to keep it topped up.
If you are reading this unfortunate thread for guidance in what unit to buy, I give my unqualified recommendation to Sony and the PRS-600. Your chances of being very happy are better than the average cell phone purchase.
I have a deal with Sony customer support - they don't bother me and I don't bother them. Should I have a problem, it is comforting to know I can deal with a real person, based in my country, and who speaks my language.
Anyone who suggests I work for Sony tells you more about them than about me.