First of all, these things last far more than a month. I have had my Visor for nearly a year and still have 4 left. And 4 of the others were either excessively abused or I didn't apply them right. I have stretched them up to 4 months at a time and they would still look quite good.

As for screen clarity, there is a small sacrifice there. I never knew what my Visor screen truly looked like until a month when I tried again to use a CompanionLink screen protector and noticed how much clearer the display was. But I took the CompanionLink protector off because my Visor's stylus recognition seemed to greatly suffer and the CompanionLink protector, while clearer, added lines to the display and was otherwise cheap. And the glare with those things on was horrible. I would rather have a slightly fuzzier display with a little less contrast than not be able to read the screen because of glare and annoying lines caused by a cheaper screen protector.

The WriteRights really do improve graffiti recognition and reduce glare significantly. And they do their primary job as a screen protector quite well, too. I still don't have even a single scratch on my screen.

And some tips for applying the screen protector without air bubbles, and this goes for any brand. Of course, make sure that your screen is spotless. Following the instructions on the WriteRights will go a long way, but I found that I just initially align and apply the small portion of screen protector that is exposed at first and just use the card that comes with it to do the entire rest of the process. I move the card forward accross the protector in short strokes to cover both sides of the protector and also peel the protector from its backing just using the motion of the card. Within 30 seconds or so the protector is on the screen completely without air bubbles. I tried this with the CompanionLink protectors with the same results (although those things are still terrible).