The MMeQ is an excellent equalizer. It is my new go to 'Massive' design for Mastering.
I've not done direct A/B compares to Mammoth nor Magenta.
Mammoth use to be my 1st call, but I very much like how AlexB organizes his libraries. Mammoth had separate presets for cut/boost ... AlexB has both in one preset.
As to the Acqua design ... they are very good, however, I prefer the flexibility of Nebula to select bands as needed ... enough times I need 2 freq choices from the same band/preset. With Acquas I need to load another instance ... Nebula I load just the band I need.
Note ... I use a custom made MIDI controller [NVC-RAK - MMeQ] that allows me to have 8 to 16 MMeQ bands on call. I like to be able to mix combinations of 'clean' and 'full' presets to a desired harmonic content.
With 90+% of my work as Mastering, I can afford a more varied/complex workflow. And to that, I'm quite picky as to what MIDI controller I design for a library [the time/dev requirement], and MMeQ has earned that.