[reactorstudios]

Yes, the DAW typically does all the tracking and mixing of layers, if your intent is to record whatever sounds you come up with. I noted that I use Cakewalk's Sonar X1, and I love it. I believe UW use a combination of Apple Logic and Ableton Live, based on what appears to be running on the computers that sit behind the Nords on stage.

The Nord allows you to store up to four parts in memory, which mean you can have four separate sounds playing at once, or stack the four parts for one really thick sound. There is no built in sequencer, though, so you can't record what you play directly to the Nord itself. Even without a dedicated DAW or sequencer, the Nord connected to a decent amplifier (it doesn't have speakers) will provide countless hours of fun. I spend a lot of time on it just messing around with arpeggios while a drum machine (usually a Boss Dr-770) keeps time in the background. When you tempo sync the Nord to your drum beat, kick-ass things can happen.
I picked mine up off of Ebay for $650 (US). A small price to pay for such a beast. If I had more money to drop I'd add the newer Nord Wave to my rack. BUT, I am mostly using software synths these days. The next time I buy a piece of hardware I'll be going for one of my dream synths, the Waldorf Q or a Moog Voyager.