I am making an assumption here, but, I presume that Durango will make use of cloud computing for a lot of things and always being online is required. The audio processing is necessary to decode, interpret, etc. However, the real knowledge database must be in the cloud. The being always online requirement won't be so crazy to consumers considering Durango is also competing against Apple TV.
For a consumer considering to an all in one entertainment server, going the Apple TV + PS4 is a more expensive route than going for a Durango. Also, the Apple TV might not play 100% well with the PS4.