Is the NHT xd System worth buying today?

Too late for the OP, but I wanted to reply to the comment about mains hum.

I believe what Stereophile documented was the self-noise of the system, not mains hum.  Mine don't hum, but you can hear hiss if you put your ear to the tweeter.  You'll find similar comments about hiss from some modern active DSP systems (e.g. Dutch & Dutch).

My Xda (the amp/dsp box) did make an annoying mechanical whine (not transmitted to the speakers), probably from the switching power supply.  I sent it in to NHT, and they were not able to fix the issue.

To me, this system is a lesson about undocumented, proprietary DSP systems.  As far as I can determine, If my Xda stops functioning, there's no way to repurpose the digital crossover filters.  Updating the amps and the DSP is also not an option without considerable hacking, or creating your own crossover filters from scratch.  

XDa was a nice technical attempt to make a very neutral speaker using DSP but today I think with much better room correction software available for both powered speakers like GLM or Dirac Live for passives it's somewhat long in the tooth.

I hooked mine up last week just to remind myself why I was dissatisfied.  Surprise, they sounded great.  The very even dispersion means they can really float images beautifully, better than my Vandersteen cloth Quatros in this regard.  And though I never got the second bass module, the bass clarity and weight in my room was satisfying.  This makes me wonder if I took the wrong path for my room with the floorstanders.

Thanks for your post daverz! Mine have been sitting for over a year (use Wilson W/P in my main system) - but your post makes me want to hook 'em back up for a spin..  :)

I'm in the market for an Xd 2.1 system to add to my 5 channel 4 subwoofer Xd set up. So anyone wanting to unload a system can do it. I bought one last year for $1400. I'm trying to build an all Xd Auro 3D set up (9 channels). I think they are giant killers, but no system is perfect. As far as noise is concerned, they are sensitive. I must pay attention to cable dressing, proper grounding and power conditioning. We have some power issues at our house that can trigger that sensitivity. It is true that the amp is the weak point as far as decades long use is concerned because it is so specialized. There is a very quiet fan deep in the power supply that can get noisy after 11 years of constant use - not too hard to replace