The super-charged ST's will easily outperform the RC-70's IMO. The Salk's have much better clarity, especially in the midrange, and the bass will be much tighter and controlled. The highs aren't fatiguing either like the Energy's can sometimes be.
For the record, this is just my opinion so don't treat it as anything but.

I also mean no offense if anyone owns these speakers; my intent is not to claim they are bad, because they aren't; the SC-ST's are just better IMO. YMMV, of course.