Re: System Advice, Please? Never Thought I'd Ask For Easy Listening, But
I assume you're considering the Denon 4308CI, not the 4808CI. The 4308CI includes a feature set that is absolutely state of the art. One aspect that I'm really fascinated about is that it is DLNA-compliant. DLNA is an open standard for interconnectivity between consumer electronic devices. Using the protocols defined in this standard, the 4308CI gives you a means to play back JPEG pictures as well as music content stored on a networked server. That server could be a toaster-sized NAS (Networked Attached Server) sitting in a closet. Or, the server could be one of your laptops. Also, the 4308CI will present a full control interface to any browser-equipped device on the network. You can fully control the 4308CI with a wirelessly connected laptop while sitting on your couch.
From a quality perspective, the Olive probably probably plays CD quality content at least as well and has the ability to play content that's better than CD. The user interface for the Olive is a winner. Olive should package that user interface as a product as it would be compatible with other DLNA systems. If you choose the 4308CI, the Olive could be used to stream music from the same server in other rooms in your house. The Airport Express has mediocre playback capabilities and includes NO user interface - content must be pushed from your laptop.
It seems you've justified the cost of the 4308CI as it's closer to what you really want. Be careful about applying that same reasoning when choosing speakers. The price for good floorstanders can skyrocket with increasing quality. Keep us in touch with your quest.