It probably depends on the ammunition you are using out of the 2" gun. A "lite" .357 Mag like a 125gr Golden Saber or that 125gr Gold Dot "lite" version Speer makes may well not be as big of a difference compared to something like an Underwood 124gr 9mm +P+ for example.

I'd be more interested in comparing a 38+P 135 and 158 to a 9mm +P in 115 and 124 out of a 2", as those are loads I would think would actually be walking around with most people packing a J frame Airweight or LCR 9mm.