I have had one for about four months now. It still works like new. I use
the Pro Tracks Plus software for PC. I wanted something I could use with both a PC and a Mac but I have found that the grumbling about software for the Mac (Bias Deck SE) is much and the very first thing I attempted, importing an .aiff or .wav, just simply doesn't work.
The Omega claims to support Sonar, CoolEdit/Audition, SoundForge 7 on XP/2k and Digital Performer and Cubase for OSX. There's help on the Lexicon website for this.
The reliability and power of Pro Tracks has been a pleasant surprise. It is supposedly a lot like Sonar (but it can't be as sophisticated since it's a freebie with the hardware).
The Omega has 6 inputs, 4 of which you can route through USB to the software. For 0-latency monitoring they say you can run a coaxial digital out of the PC and into the Omega where it is converted to analog and you get to mix it with your input with the mix knob. I have an optical digital out of my PC but I discovered that I can run a cable from my PC headphone jack into two of the line inputs and mix using the input knobs on these line ins.
The Omega and Pro Tracks supports 24/48 but some of the Pro Tracks effects don't support this rate and your sound card will need to support it or be disabled if you want the 0-latency monitoring. There are other effects to choose from but many of these are demos that add beeps every couple of seconds .
The preamps (dbx) are nice and quiet but unexciting. I got a cheap tube preamp to spice things up a bit.
I like the MBox too, especially for ProTools, but I would need an optical/coaxial converter or sound card to monitor/record with no latency in stereo. Only two tracks at a time with the Mbox (which is all I need but some people think they need as many as possible).
So far I am happy with it overall. I found it as a return at American Musical supply for $310. There's a dent&scratch up there now for $299. The Omega is probably the least expensive all-in-one solution for PC recording. And it works well. It just doesn't command much respect in this community due to the brand and price.