Sorry no_regrets, just saw your post.
I think that Robert Greene captured the differences between the Rock and WTA pretty well (and note that in my direct comparisons and his, the arm was the RB300/301-clearly the weak link). The Rock seemed to do bass better than the WTA, while vs the RB300/Rock combo, the WTA seemed a bit better in the treble. Upgrading that Rega arm, did improve the treble and detail retrieval overall, but I did that after the WTA moved on, so no chance to compare the Rock with a Moerch arm directly to a WTA. You can also see more of my thoughts on a Townshend Rock Initial Impressions" thread on Audio Circle.