I'm running MMGs, had 'em for about a year and a half now. Love 'em!! Absolutely stunning for the price point, IMO. Imaging and soundstage are simply fantastic and pretty damn good detail (though of course there are far better, albeit more expensive options).
When I first bought and paired them with my old pre and power amp I just sat around re-listening to old recordings - live and studio - to catch what I'd been missing all this time. They don't blow the doors and windows out of my apt, but that's a feature in which I'm not especially interested.
I'm running:
Crappy Toshiba CD transport >
smART DIO DAC >
Audio Experience Symphonies Tube pre >
Adcom GFA-555 power amp >
MMGs / Pinnacle Baby Boomer sub
Next change for me is replacing the Adcom power amp. I actually think my old SAE Mark XXXI (I think) 50 wpc amp sounds better than the Adcom at low to medium volume levels. So while many folks say the Maggies are massively power hungry, they can sound mighty fine driven by power amps that don't pack gobs of power.
The MMGs definitely need a sub, IMO, and I'm not a big bass-hound if that tells you anything.
Like most speakers, especially planars, they require proper placement in your space. They need some space behind and beside them to breathe. Mine are about 2' out from the back wall and 2-1/2' from the side walls.
I'm not familiar with the IIIas, but there's gobs and gobs of feedback on the MMGs (and likely the IIIas) at
Audio Asylum if you're willing to wade through it all.
I know there are at least a couple other people here running MMGs, so hopefully they'll chime in.