4. Sound
The choice of the Intel High Definition circuit is a good start. The audio quality is not bad, as we've had occasion to note. However, the results would have been better with a Creative Audigy card. That said, the sound is still not bad at all, and as we'll see it makes for some interesting possibilities.
Better-Equipped DECs
The model we tested (the z552) is the only one available in Europe (France) and corresponds to the entry-level system in the US, at $1,500 - except that in the US, it only comes with 512 MB of memory. In the US you can go for the z555 model, which carries a $2,000 price tag, but gives you a larger 250 GB disk, and more importantly, an NVIDIA GeForce 6600 graphics card. This model also includes an over-the-air ATSC HD tuner, which may tip the balance in favor of this model.
On the other hand, the z557, with 1 GB of memory and two 300 GB hard disks (one removable) costs $2,600 - which is starting to get a little expensive. My advice would be to go with the basic version and replace the ATI card with a 6600, which will lower the final price tag - unless the ATSC tuner interests you.