I've tried all 3, Supreme, SIO and SGO. I'd personally stay away from SIO, impressive at first as it's detailed, but not natural sounding. SGO definitely sounds more balanced. Supreme is the sweet spot for me, not as resolving but thicker sounding. I've had success using both Supreme and SGO in my previous tube amp. SGO in preamp and Supreme for the power.
Mundorf Supreme Vs. Supreme SIO and SGO?
For those who've gone from Mundorf Supreme to Mundorf Supreme Silver Oil and/or Silver Gold Oil, what differences, improvements, etc. did you note? Oddly I can't find any info searching the 'net on this. Is bass curtailed and resolution increased with the oil versions? Is the base Supreme more forgiving? Etc.