Wasp is the first VSTi synth I purchased (2+ years ago) yet it is also the synth I've made tracks with most recently. For me this says a lot. I find it particularly good for bass, lead, and bizzare sound effect work. While it can handle pads too, I prefer the greater modulation flexibility and lower cpu usage of other synths.
For only two oscillators, it has a lot of sonic muscle: pulse-width modulation, "Dual" switch for detuned oscillator doubling, an exceptionally ugly (read "good") distortion circuit, ring modulation, and an FM knob.
In addition, it has a decent selection of onboard effects. The reverbs and paragraphic EQ are outstanding. The phasor and delay are frustrating because the presets can't be configured much.
Wasp's amplitude and filter ADSR envelopes deserve mention because they have a nice and crisp response. Attacks and decays are very sharp. This and the 24db/octave "LP Fat" filter are really good for punchy bass sounds. Also, as you change any of the knobs to alter the envelope shape, it is repesented graphically as well.
High marks for Wasp overall for the following reasons: * Clean, punchy tone with a smooth LP filter. * Great Interface (easy to program: all controls are visible on screen at once, and graphic display of envelopes) * Great reverb and EQ. * Very affordable