I've just got a Macbook Air and I love it! But I want to make sure that it stays as nice as possible for as long as possible. I've gotten a sleeve for it, and am going to get a keyboard protector (my last one was spilled on with Mt. Dew--It wasn't disastrous, but it was close and I don't want a repeat). But I've heard that some people have "acidic sweat" and it reacts with the aluminum and causes "pitting" (small pox holes in the surface of the case). I've seen protectors for the area where the wrists rest to prevent this (and just general dirt). Is it worth getting this (and one for the trackpad)?