Supex 900 super vs. 900 mk. IV

I am really enjoying the 900 super. The bass response is very nice, and the mids are out of this world. The details can get a bit sketchy, but not bad. Does anyone have any experience comparing the two? How does the 900 super stack against the 901 mk. IV?
Did you mean the 900 or 901? The 901 was the high output version. I sold them for years and liked the 901 better. Of course I didn't have the phono preamps in those days I do now so I might feel differently if I were to hear them in my present system but both were good.