I agree with SCION. I've used PDAs and readers for 15+ years, and I have yet to find a screen protector that did anything but protect the screen, which is what they are designed to do. As far as reabability they all have made the device harder to read because they add a thin, somewhat translucent film on top of the screen. In other words, they make they screen at least a little blurry.

The key to the 900 is plenty of front lighting. Get a good reading light or use it in direct sunlight. I'm currently debating taking mine back because of the reading difficulties. It works really well when you have good front lighting, but terrible when the lighting is low. Plus I notice that it does cause eyestrain even in good lighting, something my 300 does not do. So like me, you have to decide if the high price tag is worth your application of the reader. I only use it as a portable PDF reader, so I might be better served returning it. Don't get me wrong, I still think it is an excellent reader for many/most applications.