Jritz, I looked that Nikko up. No doubt your M5s will sound great with it. But you won't know what you're missing until you try a more modern design like the Marantz.

You will "see" more distinct images with space between them, a wider and deeper soundstage and more pop and sizzle to the sound. I'll just warn you it's a slippery slope. Once you hear it, you can't unhear it.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated