It's been a few years since I shot an XD in 9mm or .40, but to my recollection, the .40 had a little more snap, but nothing to get alarmed about, if we're talking percentages, maybe 10%. The slides on the XD pistols present such a large reciprocating mass that recoil is absorbed and reduced. I'd venture the difference between the XD's and the M models are similar. Are you wanting to go with a firearm in .40? If that's the case, there are any number of softer shooting .40's these days, but if that's what you seek, go straight to the Beretta PX4. You'll not find anything that shoots .40 with less recoil than that. Not to belittle the Springers or any other firearm for that matter, but the PX4 is a miracle.