PFK:
I've had the SID Station a long time ago... bought it new for a price, that if I think back was WAY TOO STEEP compared to it's efficiency!... First of, it often crashed, scrambling every data in the machine, and the pots was flimsy and bad quality.... second, it only support the 6581 SID and NOT the 8580, which was a major concern to me, as the 8580 is much better suited for music making, as the filters work correctly (this may be a matter of taste of course), but also, the 6581 is a hell of a lot noisier then the 8580, because you can hear the oscillators "ring" when the envelope should have become quiet at the end... this is fixed with 8580.
If i may give advice, I'd go for the MIDIBOX SID instead, if you have soldering skills... made by Thorsten Klose, and it's a darn good SID synth, costing but fractions of the SID Station... much much better engine (the best if you ask me!) ... You can buy the components and PCB's from a website called SMASH TV, where you get everything you need to build it yourself. the biggest prob. is finding a proper housing for it, and assembling the whole thing... you can find info on the machine here:
http://www.ucapps.de/midibox_sid.html
(link to SMASH TV also on that page)
If you are not into building your own machine, and have a free PCI slot in your PC, you could also go for the HARDSID PCI... It's more expensive, but still a long way from the price of the SID Station... and the benefit here is, that it's integrateable with the PC sequencer, and can house up to 4 SID chips on the board! ... it also have a synthesizer architecture in software to use it in your sequencer, though I think that the engine of the MIDIBOX SID is better.... one major advantage to the Hardsid is though, that you can playback all the SID tunes of the HVSC collection on THE REAL THING!!! ... good for sampling real riffs from the original tunes (forget about that VST SID plug... when you have heard the real thing, nothing beats it!... period!

).
All in all, I'd get one of each, and are planning to actually
Then also, with the MIDIBOX SID, you'll have to find a SID Chip yourself, cannibalizing a real C64 for it... some communities on the net find this being almost a fall from grace of the greater C64 gods, but hey... we just preserve the sound of the C64
Hope this helps a bit...