I've moved on from ARC gear. Ime it sounds superficially impressive, plenty bass, dynamics, big soundstage but lacks musicality when compared to the best. I'd be happy to have it in an AV system. Macintosh are midfi at best and don't belong in a reference system.
An earlier poster suggested mixing a valve pre amp with solid state power amp. For me this is audio nirvana, i would suggest a VAC pre with a Boulder power amp.
This would give the warmth you enjoy and the bass you crave, with added musicality. A mailed fist inside a velvet glove.