Kind of surprised that nobody reviewed this synth. BLUE is a very very nice synth, it got nice filters, Sound is clear and clean and it became one of my go to synth if i want lush pads, warm squelchy basses and phat leads ( it really got a lot of good sounding pads basses and leads). Its well worth the price, just like any other synths from Rob Papen and i recommend that you get this one. One other thing i love about this synth is its interface. Blue and White is a very good combination, makes you feel comfortable when you look at it. About the sound engine, it got 6 OSC with tons of waveforms. Filters are very nice sounding, having 13 types of filtering including VOX (love it),from 6 to 24db lowpass highpass bandpass notch, ring and comb. This synth has a lot more features like the Step seq, Arp, FXs, Multi-Envelopes, fm routing, You just cant go wrong with this synth.
User interface - Very cool and clean interface, everything is organized, very userfriendly.Love the colors.
Sound - Breath taking Excellent professional Sound.
Features - A lot features. See above.
Documentation - it has manual anyways you might not need it. This synth is very easy to use.
Presets - So many good sound presets. It got a lot of banks with tons of presets.
Customer Support - i dont know never had problems with it so i never had the need to ask for their help :p
Value for Money - Very worth it.
Stability - It never crashed my pc and it is very cpu Friendly. A bass presets takes about 2 % cpu load and pads 8 % ( using an amd athlon 3200+ single core cpu )