Feature:
I got the rack version simply because I already own a midi keyboard, and the propriatory one isn't anything special. This is probably as close as you can get to a software synth-sequencer, and with hardware buttons to work with. Two oscillators plus noise, wav synthesis and 25 customisable drum-kits. 4 timbres (instruments) can play in one program with up to 24 voices. 2*32 step sequencer plus arepeggiator also play at the same time. Vocoder with pre-recording formants into 16*7,5 second buffers. USB connection is really great, you can back up everything, or change it on PC in real-time, much easier to play with step sequencer or drum-kit design). Loads are pretty fast, you can upload the set of programs in a live situation with no real delay. Two sets of outputs, midi in, out, through, and a nice on-ear microphone for vocoding that works really well.

Quality:
It looks and feels like an industry tool, metal plate, buttons are hard, only knobs are a little less robust. Backup? It is hard to have a back-up for this since it does so much...

Value:
Considering the features and the quality of the results, it fares with the synths twice the price.

Desirability:
Industry design with a lot of flashing pink(!) lights may look out of place on a rock-concert, but poeple know what it can do...

Sound:
The sound of Radias is generally excellent. The character is a little harder to specify, since it is has both clasical analogue modeling options and wave synthesis from samples options, but it is pretty much in your face, but not as warm as some Access or Moog synths. But if you need more warmth, you can achieve it easily nowadays (I use Nomad plugins in recording channel)

Ease of Use:
I am a long time computer music creator, started with a tracker on C64, but haven't used hardware that much. Radias has a nice logical work-flow, but with so many possibilities, it has a learning curve. Manual is quite good, so you can start quick enough.

Support:
No support necessery yet...

Overall:
This suites my needs perfectly, making me more creative and keeping me away from the computer in the creation phase, so that I don't get stuck in the usual sound polishing of a single phraze. I am not selling this, ever.

Feature:
It has all the normal synth functions, the vocoder is great and I love the ability it presents to morph between filter types.

Quality:
Good solid metal chasis, buttons are fine, the knobs seem a little cheap and plasticy.

Value:
Good value for money

Sound:
I love the Radias, it sits well in the studio complimenting my other synths, Supernova 2, Virus Ti, JP8080. It's top end is clean and bright and can also deliver on fatness too with a bit of tweaking here and there.

Ease of Use:
Menu navigation is a bit picky for my liking but the hands-on-ability of all knobs on front is great.

Support:
Never had to deal with supprt

Feature:
Vocoder is decent.

Quality:
My unit quit functioning after very little use. This is my second Korg piece and both have broken with very light use.

Value:
There are better sounding soft synths for one fifth the price.

Desirability:
Overrated.

Sound:
Sounds ok. Save your money and buy a real analog synth-especially since a Moog Lil fatty can be had for just a few bucks more and is built better and will last longer-not to mention sound alot better!

Ease of Use:
They are overly complicated-unless you like twisting cheap feeling knobs.

Overall:
Makes decent sound in an overly complicated way. It sounds way more digital than (virtual)analog.