I love my Duet. The price is right, set-up is pretty much plug and play and it sounds great. Just remember it's not a stand-alone DAC. It will only take digital input via Firewire and only from a Mac. That means you will have wires going from your laptop to the Duet and from the Duet to your stereo. You will need a big enough hard drive to hold all your music. Also, you can't use the Duet with another kind of transport or with a wireless streaming setup like a Squeezebox.
I didn't like the break-out cable so a friend built me an interconnect. It has just a d-sub connector on one end and a pair of Eichmann bullets on the other. It sounds better, I don't have to use adapters, and I don't have all those extra wires and connectors to deal with.
Just some things to keep in mind.
Sue