The biggest drawback with the TDM-IP1 is its video support. Because the DMPort is an audio-only input on the host device (the receiver or the HTIB), you need to connect the composite video output directly from the TDM-IP1 dock to your TV. That means you toggle your receiver to the DMPort input for the audio and then toggle your TV to the correct input in order to see the TDM-IP1's onscreen display (or the videos or photos from the iPod).
In terms of performance, the TDM-IP1 was perfectly acceptable--iPod audio quality was indistinguishable from other docks we've used in the past. Video playback of an iTunes-purchased episode of The Office looked decent on a big-screen plasma TV, but it could've looked slightly better had the TDM-IP1 had an S-Video output option. Ultimately, the video quality will depend on the resolution of the file you're playing, so expect your results to vary.
In the final analysis, it's hard to recommend the TDM-IP1. For a $40 or $50 accessory, we could be more forgiving of its limitations, but the asking price of $100 makes it hard to overlook these shortcomings. Third-party accessories such as the video-enabled DLO HomeDock Deluxe and the Keyspan TuneView for iPod or the audio-only Belkin TuneStage 2 and the DLO HomeDock Music Remote may cost more, but they offer access to iPod-based music and videos with fewer compromises. And, unlike the DMPort-only TDM-IP1, those products will connect to any TV or audio system with a free set of inputs, including your Sony receiver or home theater system.