Lanzar OPTI1232D 12" Car Subwoofer

For a couple years now I have wanted to try out one of Lanzar's Optidrive subs, but could never justify spending the money.  I happened to run across a pair of 1232d's on ebay for $250 including a sealed enclosure. 
I have been running a few different "budget" ($100-$130) subs recently...
Lanzar Heritage HRWDC12, Audiopipe TXX-AP12, and a Concept EX-12.   
By switching to the Optidrive 1232D I expected an improvement, but what I got is impressive. 
This sub goes low, and is extremely loud.  I am only running one of these in the trunk of a Contour and it is ridiculously loud at high volume.  As loud as it is, it retains surprising sound quality.  Everything from Dire Straits to Kenny Chesney to Young Jeezy is loud and clear.
It is in a 2.7cf ported enclosure tuned to 28hz.  I am running it with the coils parallel for 1 ohm on a Lanzar Opti1000.1D (capable of 1000+ REAL watts).  It plays well into the mid 20's, has a little boost at 40-50 and is smooth up to 70-80.
The ideal enclosure would be slightly larger, tuned a few hz lower to reduce the 40-50hz boost and use a larger port as I do have slight port noise.
A sealed enclosure at around one cubic foot would work well too.  It would provide a very flat response at the cost of some loudness especially in the 25-35hz range.  Those interested strictly in sound quality, or an easily constructed enclsoure would probably prefer the sealed option.
I know there are better, generally much more expensive subs availabe, but in my opinion - for $150 there aren't many subs that can measure up to the Optidrive 1232D.