What's also clever about the ND-S1 is that it serves as a digital output for the PC to which it is connected. Hence the 'PC' and 'iPod' buttons at the front of the system's top surface. The system can even be powered solely by this USB connection, albeit sacrificing the charging of a connected iPod. If I were Onkyo's engineers I'd be adding a second USB port, for additional power, to the next model.
There's an 'RI' remote control jack, too, so by hooking up the ND-S1 to an RI-equipped Onkyo amp or A/V Receiver (using the supplied cable) both can be controlled with one remote, but only if the amp/receiver has a 'dock' input setting. On the subject of remote control, the ND-S1's 'clicker' isn't the best we've used. Navigation options are limited to changing the current playlist or album, and why it isn't possible to browse the full iPod menu structure I don't know, especially when other docks offer this functionality.
The ND-S1's design might not impress everyone. For a start, does the ND-S1 need to be quite as large as it is? I'm pretty sure its 205 x 175 x 35mm dimensions enclose a lot of empty space since all it's doing is passing a signal from an iPod to a digital output, so there can't be much inside it. The plastic, sliding dock cover would probably be fine on a £50 dock but on one costing close to £150 it feels decidedly cheap.
That said, the aluminium casing feels solid whereas the whole design is intended to match Onkyo's A/V receivers and the A-5VL stereo amplifier, especially. You can also choose a silver or black finish so fitting the dock into an existing set-up shouldn't be a problem.
What should sell the ND-S1 to anyone with an extant audio system to warrant its inclusion, or the spare cash to buy one, is the audio quality. Put Apple Lossless tracks on your iPod and you can have CD quality audio without the hassle of needing to swap discs constantly. So-called purists may claim that their CDs still sound better than a digital audio track, but since the nature of lossless compression makes that impossible I'm inclined to think they're talking nonsense.