The Genesis Model 500 is a tough act to follow under the best of circumstances, and for $3.5k it's really tough.
My recollection is that it's poly-directional over most of the spectrum, with a rear-firing tweeter, dipole midrange, and then essentially omnidirectional midbass and bass. Does that sound right?
I've worked with bipolars for several years now, and they are sort of like your Genesis 500 in concept if not in execution. Ime that richness and openness is not going to be replicated by a conventional monopole speaker.
One possibility is Maggies, which unfortunately tend to be on the power-hungry side, but give 'em some breathing room and they can sound magnificent. Maybe Emerald Physics? Equalized dynamic dipoles, I was a dealer in the early days under Clayton Shaw. Used Shahinians, perhaps?
How much would it cost to have your Genesis speakers restored to service? I'm sure you already looked into that, but maybe a non-servo bass section is an option.
Best of luck in your quest,
Duke
dealer/manufacturer