Tonyangel,
the 20's definitely had more bass and better lows, and when played at normal to moderate volumes, overall better sound to me, especially over amped on my system. In the low volume range, the 10 is comparable to the 20's where the details are not drawn out so well. A bose wave radio would give both competition at low levels.
but my last memory of the 20's is decked out with footers and plinths which I never did hear the 10's with.
in retrospect, if I had bought the S2's, I probably would have stopped there, but the 20's left me wondering too much for more.