My opinion is 4520 isn't worth the difference to the 4311. If you want to save cash go for the 4311 model.
Consumer 4k is still a few years away and you can find a internet router for less that 1500, 9.2 is only for big rooms and most blu rays today are mixed in 7.1.
edit: read more about the new 4520 and they say the interface is much easier to use than the 4311. New is audyssey LFC which is like dolby volume but instead it tames the bass so it does not disturb your neighbors.
here's more info you can custom disable amps on the 4520, on the 4311 you an only turn off all amps.
InstaPreVue mode which will display small PIP previews of other hdmi devices connected to your receiver. You also get dts neoX
I agree. The upgrade from 4310 to 4311 was major: Audyssey XT32.
From 4311 to 4520, it seems there are many little improvements that are nice to have, but I can do without, for now.
Audyssey LFC is something I don't really need with a treated room, hardly anything can be heard from the bedroom beside the HT room, although the living room is another matter (the solid door is not enough to prevent the bass from leaking out). Also, if LFC lessens the "massage effect" of the SVS subs, I don't want it at all.
InstaPrevu is cute but not really useful and from what I read works best for large screen setups, i.e. PJs. As for the router, well I already have a switch and airport express in the room.