OP- keep in mind that the Sierra-1 towers were said to be better, or at a minimum, equall to the Paradigm Signature 8's, by one of our members here at avs. I believe that he did an a/b between the two at a get together. If my memory serves me correct, I believe that most of the other participants agreed.
Now granted I realize that you are only looking at the Sierra-1's, not the towers, but, the Sierra-1's share the same tweeter and overall voicing of the Sierra Towers. So with that in mind, I think that it is safe to say, you can at least count on the Sierra-1's to match the Paradigm Signature S1's. Which is a huge step up from the Studio 10 or even the Studio 20!