Anthem is local to me. they originated in Oakville, about 6 min away from where I lived. They are now in Mississauga I believe.
All the MRX520, 720 & 1120 plus the AVM60 are built on common core internals. if you notice, the firmware for each of them are the exact same file, so they sound produce is also pretty much the same. Where you get into detail differences. The 520 has a much cheaper power supply inside compared to the Torroidal ones inside the 1120 and AVM60. it is smaller than the 720, but also has less channels of amplification. They are all the same core board layout and fit in the exact same box except for the back plate is different.
The advantage of the Anthem is the ARC sound correction in it doesn't get in the way with it's processing of sound. It is that part that I found muddied the sound from everything else that I had tried. The circuit board layout of the anthem is sweet.
I firmly believe that you don't really need very much power to drive your speakers most of the time. If you want to get into the experience... with a Pioneer receiver as my head unit, I needed to turn the volume up to -10db to get a loudness I wanted and it sounded wrong even though I was using the pre-out and running through a 250w axiom amp to drive the speakers. The Anthem I can get the same loudness at -18db and it is clear sounding... but I actually only need to use -22db (not as loud) as the sound is clear and I was turning up the volume to try and compensate for the lack of clarity with volume.
Axiom: ADA1000, LFR1100, VP180, QS8, EP500, M3, M3comp
AudioSource: Amp One/A