I just picked up the 4003 at a local HT shop that was going out of business. I walked into this place and they literally had the kitchen sink for sale (and someone had just bought their Dyson cleanup vacuum) so I knew there were bargains to be had. I was able to talk the salesman down to $290, and at that price I couldn't resist. I only wish I had more to spend--they had everything priced at cost or cheaper including a room full of beautiful B&W speakers & subs going at more than 70% off retail.
I mostly use my 2-speaker setup for stereo listening, so I can't comment on its HT capabilities yet although I'm sure they are great. My setup is a Nakamichi DVD-10s and a pair of Energy C3 speakers. Not anything to write home about, yet
My old receiver was definitely the weakest link in my system, a sorely outdated 10 year-old Yamaha. Upon hooking it up, the Marantz was immediately an improvement with more detail and a more open soundstage, in general. I'm also having a great time with all the bells and whistles--I also must comment on the remote. It looks good, the backlight is a cool orange, and it can learn. I programmed all 4 of my remotes into its memory, which makes for less clutter and lost remotes.
Interestingly enough, the Marantz DAC still doesn't sound better than my Nakamichi's. I tested a bunch of CDs and DVDs of different styles thru the analog and coax digital outputs. I found the Nak's sound to be more detailed, vibrant and slightly less harsh in the highs than the Marantz.
Overall I'm impressed, and have slightly more respect for my Nakamichi player now. Shame they don't produce audio equipment like they used to.