I am a happy AS-500 owner. I had Marantz PM6004 which I didn't like because of the muffled mid-range. Though, the bass is slightly better in Marantz PM 6004 because of its 'loudness' button. Yamaha AS-500 has variable loudness control which acts differently. Yamaha AS-500 delivers 85W/channel in 8 ohms. You need to consider that AS-500 is an outdated model. It's been replaced by AS-501. I guess that the dealer is offering you a pre-owned unit; so before you seal the deal, check everything.