Used on 2 watches, 3 devices.  One watch had raised/domed face, other was flat/recessed with bezel protection.  Worked better on the raised face, even though more/deeper scratches.  Three devices: lightly scratched PDA, medium scratched phone, heavily scratched phone.  Worked well on light scratches, made it look new.  Other devices looked better but not new - like taking "scratch level" down one notch (high->medium->low->new).  Worked best with just a tiny amount of polish, using fingertip to buff (several minutes - until you can't hear the abrasive working anymore), then buff with lens polishing cloth (won't be able to use it on my glasses again however), then buff with microfiber washcloth.  Used hardly any product this way and worked well, although I had to repeat several times per item.