Vaz 2010 has a distinctive sound that has a better quality than most of the other subtractive synth plugins out there. It is a stable, mature plugin that has continued to stand up to the test of time (and against numerous other plugins that have came and went).
Many people will want comparisons to analog, real and virtual. Hardcore analog users will never be satisfied with software (to emulate analog), so those comparisons are not useful here. I have owned several digital subtractive/analog hybrids (AX73, Matrix 6, JX-8P and JX-3P) and VAZ can easily reproduce the sounds of these synths with no issues, and in my opinion sounds better than any of these. There is a polyphonic detune which will give it an analog style unpredictability if you're into that sort of thing. VAZ has pulse, saw, multisaw and sample/wavetables for oscillators 1 & 2. A third audio oscillator is possible (with pulse or saw), though it disables one of three LFOs. VAZ 2010 has seven different filter models, and they all sound great. While each filter is not labeled to make obvious what it is similar to (Moogish, etc), there is a ladder style filter that sounds really warm! The type C filter also sounds nice!
This software comes as a VSTi, a VST effect and a standalone version - all included in the purchase price. The standalone version is great for generating quick song prototypes with it's analog style step sequencers. The sequencers are very intuitive for programming leads and basses 303 style. They are also polyphonic! You're not limited to one note at a time like the 303. The randomize function is where the VAZ sequencer really comes in handy for overcoming writers block. You can control which notes are possible, over however many octaves, the percentage of rests, doubles, accents, slides and control slider positions.
My only request for the sequencer is to be able to chain together different patterns via a more intuitive method, like Buzz or Orion.
Using the arpeggiator is very inspiring. When it's activated, the notes in the step sequencer are no longer played, but the rests, doubles, accents, control A and control B are used! This makes possible some interesting bass lines and rhythmic arps! For example, the Control A slider can be used to modulate a parameter such as filter cutoff through an arpeggio.
The internal effects are great and will get you where you need to go. Using the included mixer you can get both DX and VST effects in there should the VAZ ones not be up to your standards.
It is possible to create close to full songs using just Vaz 2010, depending on your style. Acid, techno and some trance will have no problem. Wendy Carlos style baroque? Well it's better suited as a VSTi using a high end reverb in conjunction with it then.
The user interface may seem confusing at first, but it is laid out logically and the horizontal sliders eliminate the need for a larger GUI. I would like the choice to change colors though - you are stuck with the blue/orange/white deal. Not bad, but some may not care for it.
The customer support is superb! I've had all my emails answered within a day!
Value for money - for the price I paid, no question. There is no equivalent out there. None. If I had only one instrument plugin, this would be it.