I had a K5000S... It is indeed one of the most beautiful synth I have ever had. The build is great, the keybed is the nicest semi-weigthed to be ever put on a synth period.
However the reason for selling it was the sound engine. I love additive synths. But programming them from hardware or through Sounddiver (that often crashed) was killing me. Therefore I switched to additive VST synth to come out with similar sounds.
Remember, that synth is from what 1996, 1997 ?
Minimoog Voyager, Pulse 2, MS-20 Mini, Bass Station 2, Virus TI,DSI Mek, DSI Prophet 08, Nord Modular G2, Future Retro XS, KP-3, x0xb0x, MB-6582, Sammich FM, Juno 106, S90ES, Er-1, TX81Z, DM10X e-drums, Rocktron Banshee. Dr-110 and 2 lava lamps