I liked the PD-H600 well enough to buy 2. Haven't heard the 750, though I think the Marantz 8004 is more the competition than the 6004, and then it's a matter of personal preference not quality difference. I believe the Marantz units in general have a warmer/softer sound.
Teac PD H750
I'm about to purchase a new cdp. I've been looking around and just about pulled the trigger on a Marantz 6004cd. I like the idea of the usb port on the front. I just saw a Teac PD H750 cdp with the same features as the Marantz. I have not been able to find any reviews on this cdp to get an idea of what it's all about. Anyone here had a chance to listen to it? Thanks