I picked this sub up from my local shop around october and had been running it off of my CA440 for a while in a q-logic .85cu ft sealed enclosure. It left quite a bit to be desired, it would get loud enough to compete with my components, but never anything more without clipping. Yesterday i got a Soundstream Reference 604 (See other review) and this sub is extremely impressive for 115 bucks.
I built a 1.2 cu ft sealed enclosure for it, and am sending rougly 350 watts to the sub. It gets relativly loud considering its sealed, and receving 150 watts under its rms. It also sounds very good, plays accurately up to around 95hz, and is pretty tight for the most part. In comparison to 2 subs i had lying around the house which i hooked up to the same amp, and put in the same box, it killed them, Kappa perfect and mtx4000. The perfect sounded a little tighter and accurate, but spl suffered greatly. The mtx well, not really worth talking about, got loud, but distorted like mad, i was also sending it quite a bit over its rms, but thats besides the point.
In comparison to the ED K which seems to always end up in the same boat as the CM3, the K probably wins by a bit. It costs a little more, but in the end probably a better driver. Though, if you want the convenience of buying at a local shop, and saving around 45 bucks, the CM3 is a very good way to go. I heard it ported to 32hz at my local shop, and it was quite loud, beat the heck out of most of the other subs they had there. I just don't have the room in my car for it. Anyway thats it.