I'm also on my 3rd Ti/Sc model, which are J-frames, by the way. The 386SC/396Ti designate the L-framed model numbers. Both myself and my wife own 342PD(.38+P) models, but I recently started carrying the 340PD(.357) version.
I don't know why the PD(black) models are lighter than the silver/grey ones, but my 342PDs are listed at 10.8oz, with the magnum version weighing an even 12oz.
Both of us consider them the
ultimate concealed-carry weapon, and between the two of us, have tried everything out there(or so it seems). I think they're a pussycat with .38 & .38P+ loads, as with my steel-framed Model 60s, but the .357mag loads are a real
pain.
I have my carry rounds specially loaded to .38+P++ pressures by an area outfit(legal issues). They are bottom-end .357 data, but greater than .38Spec+P+. It's actually just 5.8gr of Win231 pushing a 158gr Speer Gold Dot(JHP) from magnum-length cases. Very accurate and easily controlable. Although my tests have only been done on water-filled milk jugs, 5-of-5 showed very good expansion.
I hope you find the information you seek. I think the reduced weight of the new Airlights is well worth the extra cost, since
carry consists of 99% of the firearm's employment. If they built a 5oz. J-frame in .38/.357, I'd own one of them also.
What do ya' think, a polymer version with stainless-steel barrel & chamber liners? I bet it's not too far off.