My original Physix cracked earlier this year so I haven't thrown them up against each other but my impression is they have a very similar motion at the end of the pattern but the Infinite is a lot cleaner through the fronts/mids. I think at the same surface they would be relatively close to each other but my Infinite was pretty shiny out of box and I left it that way.  I think there is enough separation between the 2 if you shine up the Infinite a bit, at box surface I think it would be a waste to have both.

Infinite is really good, but the cover is quite a bit stronger than the Astro. It comes dull so if you’ll likely want to apply polish to get a similar shape.