I haven't seen or heard the NuForce, so I don't know how it compares to the 990. Info on their
site is a bit scarce. The remote's stylish looking, but I wonder about its practicality (unlike high-end two channel gear, home theater gear has to be designed under the assumption that you'll use it in the dark - that's why backlit universal remotes are so prevalent).
I had to hunt around a bit to find a manual in hopes of having it shed some light on things like bass management, video switching, and such). The manual is a whopping 16 pages long (compared to the 990's 52 pages). From what I can tell, the bass management consists of a single adjustable crossover applied to all small speakers, the video switching lacks any transcoding (composite inputs appear at composite output only, s-video inputs at s-video output only, and component inputs at component output only), and the digital audio inputs are not addressable (so even though there are seven digital inputs on the back, you can really only use four of them at once).
Functionally, the NuForce is clearly more of a "purist" processor: fewer input options, a really pretty remote that would be difficult to use in a dark theater, and a feature set that would have been very respectable five years ago but looks a bit sparse today. Sonically, I'd expect it to be a very good performer, but I have no first-hand evidence of it - mostly, I'm assuming that something designed with this mindset would have to be geared strongly toward pure good DAC's and clean analog design simply to justify its existence.