On my first look at SimSynth it seemed pretty average. A standard 3 oscillator analogue emulation soft synthesizer. However, on actually trying it out I was pleasantly surprised by the warmth and fatness of the sounds it can produce. This is due to the excellent filter. It has an emulation of a State Variable Filter, which is the sort of filter used in some Oberheim synthesizers. This gives it a different sound to the filters in most other software synthesizers - not better for every purpose but definately a differentiating factor. The filter selection also has a preamp to allow you to boost the signal before sending it to the filter to get a bit of distortion.
So what else is included? Each of the 3 oscillators is switchable between triangle, sawtooth, pulse, noise and sine wave, but hidden behind the sine wave is a 16 band harmonic syntheizer - nice for slightly different effects. There is also a warm button which adds a detuned second frequency. The envelopes (amplitude, pitch and filter) are all graphical, which is more flexible than the standard ADSR format. Usefully a grid is provided allowing you to synchronise the envelopes to the speed of the song. The same window lets you create a riff for previewing your sound. Lastly there is an effects section on the output providing chorus/flange, delay and some limited EQ. My only proviso about the program is that it seemed to lack some 'crispness'. DirectSound is supporting enabling very minimal latency.
The shareware version can be registered for $35 and this allows saving to WAV files.