Compare a new 6" GP-100, KGP-161, to a new 6" S&W 686, SKU 164224. The GP-100 weighs in at 46 oz vs the 686's 44 oz (43 oz if you go for a 7-shot 686+.). The MSRP price of the S&W is about $80 more, street prices are closer.
Now, look closer.... the cast steel Ruger has a massive shrouded barrel, the forged/heat-treated S&W has a less massive full lug barrel. Sure, the sideplate is removeable from the S&W, undoubtedly 'weakening' the frame a bit, but the N-frame is not much thicker - and it is designed for .44 Magnums. With any normal SAAMI spec'd .357M ammo, you won't ever 'stretch' that L-frame. While you are looking 'closer', really look closer... I rejected every 4" GP-100 for the obvious tool marks and QC boo-boo's, almost never a problem with S&W's (I've had one 629 come with loose sideplate screws - could have been loosened in route, even.). My locally ordered Redhawk had burst casting bubbles between the chamber bores - fixed, of course, by Ruger changing out the cylinder, etc. Every Ruger, except my SRH, I have bought has been delivered as a work in progress. I'll take S&W, but either will serve most folks quite well.
Stainz