I have an intuos 3 and i am very pleased. i ve bought inkling and i am not. Since wacom is the only company that manifactures tblets for artists the numer of professional artists that had bought cintiq does not mean mucht to me. I ve read that instead of glass it not uses plastic therefore thats why there are complaints about scratches. A protector would be a good idea but it seems that there only one company -in amazon.com that manifactures them and there are no user reviews... maybe i ll wait till wacom decides to use gorilla glass or another company do so....
Use common sense. Don't wear a watch with sharp edges while you work. Don't set things on top of the screen. Don't use pointy objects on the screen other than the pen that comes with it.
If there are so many professional artists using these and loving it, why aren't they complaining about scratches and stop buying them? You also have to think about how much is "scratched" to those people? Are they talking tiny, barely noticeable lines that happen over months and months of hard use, or is it deep noticeable grooves that happen every time you use it? I've personally never heard of the latter happening unless the tablet gets abused by someone pressing way too hard or they were irresponsible with caring for it and damaged it with something other than their pen.
There may also be screen protector sheets you can get for a Cintiq just in case, so look that up on Wacom's website.