I have the Fons and Porter's "Klutz Glove. I remember to use it about half of the times that I am rotary cutting. Or else I can't find it in the mess on my cutting table.
I don't really know if the glove would save your finger from being cut into. A while ago I asked on the board here if anyone had ever actually run their rotary cutter into their finger while wearing their klutz glove, and if it really protected their finger from getting cut. No one responded that it had protected them.
If nothing else, the process of putting the glove on reminds me to be a little more careful.