Caught these babies on a special sale so that now I have 12 of them laying around. They really do work and, as long as you follow the directions, do not micromar or swirlmark any worse than a microfiber. A rather brilliant thing, actually.
A good car wash brush and a bucket of soap every few days will keep them off, then wax the bumper twice. I haven't noticed it much yet on my G6, but if the bugs start getting into the rad, I'll probably install a screen under the hood so they stay out!