The Denon 3312CI and Marantz SR6006 looks like the same.
Both have in common key features:
- Frontal HDMI input
- Dual HDMI output
- PLL for jitter reducer
The difference in power is probably more conservative Marantz rating.
Look at the inside pictures of both receivers and they are the same.
Denon 3312CI http://www.carltonaudiovisual.com.au/?q=node/view/1615
Marantz SR6006 http://www.areadvd.de/lm/AV_Hardware...60065006.shtml
The key difference is the sonic signature (the third octave a little up in the Marantz).