Conclusion: On the surface, the Denon AVR-4520CI makes a pretty strong case for itself as a flagship receiver. Its combination of relevant features, consistent and reliable operation, and a straightforward user interface makes interacting with it on a daily basis a fairly pleasurable task. Its multi-room audio/video capabilities would also serve a whole-home, networked system well.
Pros: Smooth, fatigue-free treble, Good bass clarity and definition, Well-thought out feature set, Outstanding video processor
Cons: Audio performance outclassed by the competition, Sound lacks dynamics and punch, Recessed, flat, and lifeless-sounding midrange, The most irksome auto set up program we’ve used yet
Conclusion: There's a huge amount to enjoy here. An exhaustive spec gives you everything you'd expect in an AV receiver and much more, coupled with a cohesive, engaging and easy-to-enjoy character. Only a little excitement and scale is missing compared with its peers.