Good Product or Nonsense?

my 2 cents:  I've used 2 or 3 spray bottles of Optrix over the course of 3 or 4 years.  No negative results, no staining, discoloration or negative playback issues.  Also use it on DVDs and find it actually will help a well used DVD play better.  If a disc gets 'stuck' or skips, I've cleaned it with Optrix and in several cases the DVD played minus the hick-up. Gotten in the habit of cleaning DVDs prior to playing them.

As far as sonic benefits on CDs, it seems to do what it claims; never seen a residue or haze after cleaning discs and playback sounds great after application.

Personally I'd never use Windex on a CD.  Windex on glass has never worked for me. We use SprayAway on windows, mirrors, and windhshields.  Windex has always left streaks, SprayAway works much better for us.  The idea of using eyeglass cleaner makes sense, have to give that a try.