Another thread I think you might find relavent is this :
slut on a 909, 808, or MD?
The 2nd poster has the same feeling as I do. Sound is most important and I can do similar synthetic drum sounds like the MD with other software. The Jomox drum machines have a deep strong analog sound, which I like much more than when I had the machinedrum. With that said, I still am quite interested in getting a Spectralis as it seems to have great everything and is nice and groovey. That analog synth in it is really cool. And it can do a variety of synthesis like FM and whatnot. You can check out some examples here, but there are more different synthesis examples in the forum. (scroll down)
Radikal Technologies Spectralis Synth/Filterbank V 0.97 - (eBay item 300183634522 end time Dec-25-07 10:03:44 PST)
Oh yeah, and you can import your own samples and use them as waveforms in the Spectralis and tweak them like any other sound in the DSP engine.