Plenty of videos on Youtube showing +P 38spl. HP ammo like Gold Dots getting rapid expansion, wound channels and penetration equal to and once in awhile greater than a .357 out of a snub.
When you start going up in barrel lengths, that's when the .357 starts edging out over the .38spl +P. As far as defense goes, the faster follow-up shots and recovery make the .38spl +P a better snub round in my book since the difference is far too small for the extra blast and recoil. The only snub (however far from lightweight) I like shooting a .357 out of is the SP101, otherwise it's my GP100, K frames or other medium-large framed revolvers. BTW, I'm not recoil sensitive since shooting the S&W500 is a fun day at the range.