I have 2 12" 04's and I've heard a sinlge 12" 05. The 04's are more suited for a sealed box and IMO, and more sq oriented. They sounded amazing in a 2.5ft^3 box (1.25 per chamber and driver) powered by a shared 1100W. They were loud enough, clean, precise and overall very musical. I have them now in 3.5ft^3 tuned at 34 hz and their sq has diminished noticably to the point where I'm either building a new box, or going back to sealed. They're loud and sound ok doing it but they were much much better sealed. The '05 that I heard was ported at 2.25ft^3 at 32hz and it was louder than hell. It was in a 300zx which helped its case. It was louder than my 2, again install dependant, but it still had a nice amount of sq. Overall, an sql driver that lends itself to spl...
Just my $.02...