I purchased the RW-12d from Newegg and received it on Thursday. I haven't listened to many others, but here is my take on it.
I had the 10" Harmon Kardon 200 watt sub that came with my HKTS system. I wasn't impressed at all with that sub. Like you all I had to jump on that deal for the Klipsch sub and I am very glad I did. The klipsch sub sounds and hits much better. I can now feel the vibrations everywhere in the house. I can even feel the lows when you cannot hear them, which is cool. My wife has to fix all the pictures in the house after listening to the system. I would definitely purchase this again if I had it to do over but would get something else if I had to purchase it at its normal price above 500 like a sealed sub.
I have heard my friends Velodyne CHT-12 and think the RW-12d sounds better and hits harder, might be because of the higher RMS output. It definitely fills the room better than his. There were a few occasions where I heard port chuffing on transformers 2 and Pandora but did not hear it on transformers 1. The only time I hear the port chuffing is on very fast low frequencies.
If any port chuffing bothers you I would pass, but if the occasional port chuffing doesn't, it is an outstanding sub and I love it. Also this sub has a reputation of being boomy, but I have not experienced this in my setup.
I think that music is awesome on this sub and haven't heard any port chuffing or heard it having a problem keeping up. I was very impressed with the amount of bass output playing Usher's Yeay song. Pictures were falling of the walls.
I am running a Denon 3808 and HKTS bookshelf speakers and the sub is set at +4 on volume and +1 on the amp.
Hope this helps!