The X 4000 looks interesting.
X 4000 review:
It seems to be a 4520 - "lite".
Most of the features, but much cheaper.
The key features are still there :
- XT 32, Sub EQ, 7 HDMI
What you lost won't affect most users:
- 9 channels instead of 11
- build a little lower
- no more gold plating on binding posts
- 24 000 mF instead of 44 000 mF capacitance
If it sounds good in stereo, then it will carve out sales from the flagship AV amp. It will also be a good alternative as a processor, especially if you don't need more than 9 channels. It costs a fraction of it's cousin the Marantz AV 8801, and does most of what that processor features.