Part of what sounds so nice with a good dipole speaker traces back to its dipole radiation pattern, and what it does right as far as the reverberant field when set up correctly.
Let's start with a quick look at the sound fields in a good recital hall. We have a very clean first-arrival sound, then a few weak reflections off the people in front of us, then after a fairly long time delay, the reflections from the walls start to arrive. Since the walls are diffusive rather than absorptive, this reflected energy is not only powerful but also spectrally correct, and from it we get that rich timbre and sense of envelopment and immersion in the music.
When set up correctly (preferably a good 5 feet out from the wall), dipoles come reasonably close to approximating this situation, within the limitations of our room size. We have a nice clean first arrival sound, then relatively weak early reflections until the spectrally-correct backwave energy arrives after bouncing off the wall behind the speakers. This relatively late-onset, powerful, spectrally-correct reverberant energy significantly enhances the timbre, envelopment, and even clarity of the presentation (I realize that last claim is somewhat counter-intuitive, and can explain it if you'd like).
A wide-pattern monopole speaker usually falls short of a correctly set up dipole in two areas: The spectral correctness of the reverberant energy, and duration of the path-length-induced time delay. Both of these matter to the ear/brain system.
I've done some work with alternative polydirectional configurations that fire their spectrally-correct reverberant energy off in a different direction, for situations where it's not feasible to position the speakers far out into the room.
Nothing against a good monopole - I build those too - but there are things that good dipoles, or other types of polydirectionals, do better than monopoles. And if that's part of what you've fallen in love with about your dipoles, it's hart do go back.
Imo, ime, ymmv, etc.
Duke
dealer/manufacturer