I tried it before, winrate vs bronze dropped by ~3%. Maybe the variation is just due to the changes in the arena and not on the actual performance of the deck, but I guess I'm sticking with this version.
The SoB version is strangely balanced: 1-card modifications to it (changing number of swords, phoenixes and SoFr) seemed to drop winrate vs AI4 by ~10%. I even tried taking stats on this version again and it's still ~70%-75%, while the modifications are always only 60%-ish.