I was looking for much more than my entry-level quality materials, with a constraint: use Linux as much as possible, because I have multiple operating systems including FedoraCCRMA, ubuntustudio, Tangostudio and KXstudio, and other time time experimentation.
I only used because there is everything you need in preamps, phantom and inputs of all kinds for instruments, microphones and power lines including optical digital.
For now, only a little midi keyboard with virtual synth for my home studio is in the works, but I is electric guitars, piezo, low active / passive, and various acoustic instruments with a microphone Rode NT2A. the number of physical inputs enables stable for each of my instruments wiring, simplifying management studio I hope. I will update after restarting the studio.
My configuration: Ordinary VAIO 2010 64-bit, 8GB of RAM, two processors, external drives with USB 2.0. and Windows 7 X64. The sequencer is Reaper in general, except Linux: Qtraktor, Audacity, under Qjackcrtl JACK.

UTILIZATION

Windows drivers are stable, provided to avoid plugging and unplugging hot, she loses control. Management software are delivered with more than stable, but require a little practice to understand, we are dealing with a full console routing, not a single sound card "IO".
I have not reached the limit playback / recording, but 35 tracks effortlessly read with some VST effects at the same time do not fear him visibly.
For updates, I do not know, buying is still new, it has had an update.
As for using Linux DC (USB2.0 compatible) mode, it comes up with a little practice and savvy to put in CC mode, but drivers "class compliant USB 2.0" for my Linux distributions need a patch that I have not been able to find. In short, it is recognized but does not work. AAARRRGGGHH!
So, not possible to measure the latency and capabilities in Linux, which would have been nice and would have allowed me to test listening too, or the number of tracks etc.. I look forward to updates version hoping the best on that side.
I put great only as regards Windows.

GETTING STARTED

Easy installation with the supplied CD, or the executable downloaded from the manufacturer's website.
General configuration easy with software:. A "settings" for the buffer settings, sample rate etc, the other "TotalMix" for routing, effects, mixer in all its forms.
Incompatibilities: yes but for once the fault of Linux and ALSA bug that covers all class compliant USB 2.0, so all hardware specifications USB2.0. There will be no better off with another manufacturer.
The manual is clear and sufficient in English, 102 pages still quite dense but useful. For Francophones only they can usefully refer to the manual sister UFX, which exists in French and corresponds to almost everything, including routing, Totalmix and its uses. More.

OVERALL OPINION

I've had a few months, but I use it in the studio at the moment. I had a Multimix USB4 two Line6 Toneport before and I have not tried anything else before buying.
Like most sound clarity: with the computer speakers can already hear a difference and clarity in my own mix that I did not hear before, and with the studio monitors or headphones, the listening crystal. I guess (and hope) that future recordings will benefit from the clarity and I can get better at recording and mixing. Too bad for Linux, it is shredded for now, but again, this is not the fault of RME ... Although the specifications of public driver, or a Linux driver, considering the price, it would not be well received.
In terms of money, I'm not disappointed but I can not compare, with no other materials of the same range. At the same time, for these kinds of opportunities, not to mention the sound quality, though a bit subjective, routing, number of input / outputs including digital, I feel there is a good value.
With experience, I would do this choice, I feel like a little gem interface, this is the first time I material of this quality and it feels good.