I've only tried '57 Classics in a few guitars - an Orville by Gibson LP, a Gibson ES-339 and a CS-336.
In the LP I liked the singing tone but they were a bit too soft and mushy sounding - I probably would've changed the bridge pickup, at least.
In the semis, they're a little brighter and again I quite like them, although I'd still like a bit more crunch and tightness from the bridge pickup (that's Alnico II for you). But I don't fancy the hassle of attempting a pickup change on a semi, it'd be a nightmare.
They're not the best, but I think they're my favourite Gibson pickups.
I haven't tried Stormy Mondays as a direct swap for '57 Classics, but I think the tone is "similar". The SMs probably have a little more clarity, less mush on the wound strings. I couldn't say more than that really.