Hi jcollins1777,
I'm uncertain about the quality of current Marantz components. For years, Marantz was owned and built by Philips, which have had lousy quality control in the past. Marantz also seem slow to pick up and integrate new technology. Now Marantz is owned by the same holding company that owns Denon, but I don't know who builds the Marantz line or if the quality control has improved.
If you do careful A/B comparisons of well-engineered modern A/V receivers (switch out the tone-control circuits because none of those are absolutely flat, which will produce audible differences in sound quality), there are not significant audible differences unless the units are pushed into clipping or near-clipping.
That said, I'd stick with H/K, Denon, or the new NAD, all of which will drive 4-ohm loads like the Axiom M80s. This isn't an issue with the 8-ohm M60s, but it nonetheless speaks to beefier power supplies that don't go into protection mode or current-limiting when confronted with lower-impedance loads. I've been using an H/K AVR525, which I generally like. In many years of testing, writing and editing equipment reviews, I've never detected audible differences between solid-state amplifiers that couldn't be attributed to measurable differences in linearity (see my comments about tone-control circuits) or eccentricities (rare) in design.
Regards,