Pros: Inexpensive, versatile, charges iPod, bypasses iPod's DAC so you can use a better amp, very handy as a dock.
Cons: BRIGHT sound reproduction, on the verge of harsh.
I wanted to bypass the internal iPod DAC to get some better sound quality and plumb the output into a better amplifier. The Pure i-20 allows you to do this, but that comes with some drawbacks: this is by far the cheapest iPod DAC on the market, and it sounds like it's the cheapest. The sound quality that comes out of this DAC is bright by any standard, on the verge of harsh. I find that I can't turn the volume up on my amplifier very far before the sound produced from the DAC output on this device becomes so bad, that I have to take my headphones off and stop listening to music for a while.
It does make a nice iPod Dock, but it doesn't do anything by itself other than allowing you to hook your iPod up to some other audio component. It has no speakers, just an array of outputs on the back panel (which does include Toslink and video, which some may find useful).
There is a reason this is an inexpensive unit. It really is not worth the money. I wasted $90 bucks on this thing, and I honestly wish I could return it. Sadly I've had it too long. It is a very handy design, if you're into that kind of thing. It holds my iPod nicely so it doesn't wander around my desk at work, so there's something to be said for that. It charges the iPod so I don't have to keep the cable connected to a USB port or charger (which would have been 70 bucks cheaper to buy).
Basically, I'm not happy. I didn't want to spend hundreds more on what seemed like the only other alternatives to this device, so I took a chance. I'm sorry that I bothered. On the other hand, if I keep the volume set low, it's not so bad. I plumb the output into a Bravo V2 and use it at work, and after getting used to it for a couple weeks, I've learned how to deal with the harsh high end: keep the volume low. That way, my ears aren't glowing bright red when I go home at night.