My initial listening impressions are that this is overall a pretty good driver.
To reiterate, I'm presently running the driver IB on a 500w amplifier with a lowpass crossover of 63hz @ 18db/oct.
Sound quality wise the driver is pretty well defined. This no noticeable overhang. The driver is tight and accurate on fast bass lines and fast transitions. There doesn't seem to be much blending of the various notes. For the most part they seem to be well separated and distinct with good transitions between notes. On faster bass lines, like those found on Mudvayne, and on more complex notes that transition fast or are layered the driver has no problem keeping up with no lag or overhang. It does an acceptable job of sounding "real", instruments sound like instruments. There also doesn't seem to be exaggeration of the notes. And with proper level matching the sub blends well with the rest of the system. The driver isn't perfect, but it's a pleasant driver to listen to with no obvious or obnoxious deficiencies in the way of sound quality.
Output wise the sub is fully capable of getting sufficiently loud at frequencies above approximately 35hz. Enough to be overpowering if so allowed....certainly more than enough output to suffice for all but a true basshead. I honestly haven't got a clue exactly how much power I'm running to it (amp is rated 500w, but I'm certainly not using all of that juice), but from fiddling with the settings I can tell it's capable of more output than I'm utilizing from the driver for daily listening.
On the downside, however, in this particular installation the driver lacks impact in the lowest half octave to octave. Of course, it doesn't take a genius to figure out from the looking at the specs why this would be so. A lower Q higher Fs driver is inherently going to have a weak bottom end in this alignment. Running IB however does give the driver some advantage in low end compared to a sealed enclosure. I did end up bumping 20hz - 32 or 40hz (can't recall off hand) by around 2db to give it some additional low end without trying to overly stress the driver. This helped some, but it's still a little lacking. On tracks like Planet Kryptonite and Beasty Boys the low end is present, It isn't non-existent, it's just not strong.
For this reason, I could not foresee running this driver in a sealed enclosure as that would simply serve to further reduce the low end output.....unless you had the available power and excursion to EQ in the low end. I do however believe this driver would greatly benefit from being ran ported in a low tuned enclosure as this should increase output in the last octave where this driver needs assistance. Sealed would probably be acceptable for just a good sounding daily driver setup.....but expect the low end to be further impaired.
Some of my listening material to test this driver all around for accuracy, performance with different music genres, output, etc;
Puscifer (testing for output)
And a whole lot of weird **** at Dave's house, most of which I'd not heard of before.
As of right now, I'd probably rate this driver a 7 out of 10. Sound quality is good while not prefect. Output in the upper passband is more than sufficient, while the low end is lacking in this particular installation.
Right now if you were to ask me if I were going to keep the Dcon in my car or reinstall the Shiva-X, I would probably have to say the Shiva-X will be going back in. Why? Well, the sound quality of the Shiva-X was at minimum on par with the Dcon....the Shiva-X seems a little more refined in definition. But, in my particular installation, I also need the low end output the Shiva-X provides since I plan on sticking with IB. However this statement could be different if we were discussing a different alignment, such as a ported enclosure. We'll see how this weekend pans out.....hopefully I'll be able to test it in a ported enclosure.