I bought this a few months ago, partly because I fancied it as a 303-ballpark synth, and partly because of the rare and to me, coveted, wavceform features. The 11 waveforms include sine wave, and 5 variations of sawtooth and square. All of these waves sound different from eachother and are PWM-able. I know some synths can do this, but it's a rarity and EVERY synth should be able to do it! Static oscillators are a crime. PWM is achieved on the other waveforms by pinching the wave at the beginning and end of it alternately, and it even brings the sine wave to colourful life.
Hard sync and ring modulation round out the tricks of the dual oscillator section, but without a way to sweep osc. 2's pitch, they're of limited value, providing only static timbral variation (though there's always automation ;). Overall the oscillators sound fantastic.
The filters are juicy and come in three flavours, all lowpass, but with different steepness and characteristics. You'd never guess this synth was made when it was, judging from the sound. Control is limited for the most part to the parameters available on the tb-303, but this is so good at doing what it does, I don't really care. If you really want to play pads on it, multitrack it. It was made to make mono lines (of the bass or lead variety) which cut thru the mix, and it does that beautifully.