I watched a youtube video where they compared Aquapel & Rain-X side-by-side.
The R-X started out better, allowing rain to roll up the glass much more quickly. But then lost its mojo way sooner.
However, the way the AQp started out, it remained that way for a much longer time, like a few month's and still beading up the droplets. Where the R-X hadn't been working at all any longer.