I'm most likely to use a QSC K series as a wedge floor monitor (similar to the Fearless cabs) and I'm lucky enough to be able to insist on PA support for the venue we are in so directionality isn't such an issue. But it could be for rehearsals.
For guitar, my current guitar cabs (loaded with neo Creambacks) have a very narrow field of dispersion and, without PA support, it makes the mix extremely uneven from within the audience. You're either in the line of fire, so to speak, or you can barely hear a thing. So maybe the K10's would be a better option.
OTOH I've tried the Kemper into the Aux In of my Shuttles (power amp only) and it sounded surprisingly fantastic with good dispersal and articulation for both bass and guitar. But the Fearless cabs are a little unwieldy, I've baulked at taking them anywhere in a taxi but I do have my own storeroom at the venue so I could just bring one amp and one F112 and leave it there.
It seems there's a bit to think about for the tradeoffs.