I suppose it depends upon what you're going to use it for, and how big your room is. The RW12d seems like it might be the better choice for someone who does mostly HT, or is looking for more "wow" factor. The S10.3 sounds as though it's probably a bit more faithful, so it should be a little better for clarity and music.
Wow I have been looking into the same comparisons for the 2 subs and wondering if it's worth the extra $100 for the Klipsch. I currently have an Alison AL-10 that I'm looking to upgrade and it seems that both subs are fairly close.