I also have one of those (although it's a RI with a hardwired cord, exactly like Melly's except mine is silver where the black is and black where the green is. (the new RI has an adapter and different knobs.) Price was $90,used) I agree with Melly, the Filter Matrix is the best part. I actually use that almost exclusively and keep another flanger on my board so I can use the Electric Mistress just as a filter.
"One: Where's the fife? and Two: Gimme the fife."