The X4000 seems like a great unit, but what are the additional features you referred to that the 4311 does not have?
Peng, you pretty much listed them in the X4000 review thread... "The 4000 has newer features such as 4K and Instap
review but the 4311 has 11.2 processing, 7.1 analog in, 9 channel of amps vs 7 for the 4000, 4 ohm rated, and plays HDCD for people who owns them."
I don't use the 4K upscaling now, but I expect my next TV will be 4K, and I won't have to replace my AVR.
And honestly, Instapreview may be useful for some people... but I don't use it.
I use an XPA-5, the only channels powered by the AVR are the rear surrounds, so the extra 15W of the 4311 is not an issue for me.
So when I looked at the features of both, the one feature I saw that could, (at least in my mind), obsolete my AVR as soon as I bought a new TV, was the 4K-upscaling. I didn't anticipate using any of the several features available only on the 4311. So I went w/ the 4000.
BTW, thanks for all your comments and advice. You are one of the people here who I do "listen to".