Been running WDW for a short while (2x12 or 4x12 center, 2 1x12 satellites for FX), was glorious in the rehearsal room but once I heard what some FOH guys made of it, I stopped more or less immediately.
When you think about it, all of a sudden whatever unknown random FOH operators get in control of your FX mix and stereo spread. The last thing you want, really. Heard some recordings and sometimes the FX were barely audible, sometimes it's been almost only FX. Meh!
Similar things go for stereo. I was running my 4x12 splitted, so when listening to the actual thing, the stereo spread wasn't that wide. But pretty much any random mixing guy would pan the two channels L/R to the extremes, which was just nonsense.
Add to this potential phasing issues on some stages.
Went back to mono. Way less hassle in pretty much any aspect. I would possibly go stereo if I had an original band playing regularly with an own sound guy. But otherwise, no thanks.
Well, ok, for fun and out of interest, later on I tried what rather was a "dual mono" setup. Boogie MkIV through a 2x12 cab plus a Laney LC50 1x12 combo with an additional 1x12 cab. Used the entire thing as a clean pedal platform and was running a mono pedalboard's splitted output signal into both amps' clean channels. That's actually been quite glorious, very punchy and partially huge rhythm sounds. It's also been easy to deal with live as it didn't exactly require dual mic-ing, so for the 4-5 gigs I played with that setup, on 2 I only used the Boogie's cab, the additional amp was for stage fun only.
Anyhow, these days I'm running strictly mono, even on IEM gigs. I'm most often playing with keyboarders, so there's absolutely no meaning in adding another stereo wishy-washy element to things.
Fwiw, at home I'm using stereo delays and reverbs all the time. But that's an entirely different story.