The Recoil Myth is alive I see
I didn't have any scientific gauges, so this isn't any sort of real proof, but I've shot my PTR-91 and Sprinfield Sar-3 right next to my FAL.
I like them all, but the 91 series guns do seem to recoil more than the FAL when using the same ammo. I haven't weighed them in a while but I think they are both really close in weight. I think the FAL is a softer shooter.