In practical terms, looking at the BBTI data for 124gr/125gr rounds fired from real guns with 3" barrels (no data for real 9mm guns with 2" barrels), the 357 has a 100-200 FPS advantage.

And that is despite the fact that the gun used for the 357 was a revolver with a barrel to cylinder gap - which leaks pressure - and the gun used for the 9mm was a semi-auto with no cylinder gap to bleed off any pressure.

Even when you look at the extrapolated data for 2" barrels the 9mm and 357 appear to be pretty much a dead heat. IMO that would certainly seem to indicate that the 357 is the more potent round as far as I can see.