Summary: If you own an iPod and you have an AV Receiver for your home cinema with a spare audio in (I use coaxial) then you have to buy this appliance! It produces CD player quality music from your iPod that appears only limited by the quality of your front speakers. A song that always showed the limitations of regular iPod docks was Radioactive by Imagine Dragons. This device allows your speakers to play the complete bass of that song without distortion.
Summary: I was looking a for a dock for some time now to transport my files off my iPod Classic in a pure digital format. There have been some other docks prior to the Cambridge Audio iD-100, but none has impress me to buy. Some members on the forums i read experience problems with the others, so I stayed away from those other docks. When the ID-100 was release, I loved the asthetics of the dock and that it also supported the iPad.
Summary: I purchased a Wadia 170i a few months ago which I linked to an older Adcom audio system using a Cambridge Audio DacMagic. The quality of lossless (m4a) audio files played with an IPOD Touch were outstanding. Although I initially purchased the Cambridge Audio iD100 to connect my IPOD to a Sony AV receiver's optical audio input, I have boxed up the 170i and I am now using the iD100 with my primary stereo.
Summary: $300 is a lot for an iDevice (iPod/iPad/iPhone) Dock. Yes, you can buy a standard Dock for $20 (non-Apple). But I've been down that road and have never been happy with the sound from the analog output of a normal Dock - even a genuine Apple Dock. I even tried a pre-amp to help improve the sound, but it did not help that much. The truth is that iDevices are not designed to be connected to a hi-fi system through a normal dock.
Summary: I upload my music to a 160gb Classic iPod in Apple Lossless which yields CD-quality. Since iPods have inexpensive DACs built into them, the sound via the headphone output isn't fully realized. When the Wadia iPod dock became available it became possible to extract the pure digital output, bypassing the iPod's DAC. The problem was that the Wadia is about $379 and doesn't provide good control of the iPod with its remote control.