I've got some glass polish but I've had only marginal success using it.
What I've found is they're abrasive enough to remove stubborn water spotting, and really clean windows like they're new...but they do very little for actually correcting scratches from wipers, etc. You will initially see filling that will make the scratching look better but as the fillers wear off the scratches will come back. This was all with a high speed rotary buffer.
Andy