Gang, I recently installed the a Super kit in my MB from @pinwoofer.
Originally, I had purchased just the cabinet upgrade for this title. It really helped, but after installing the full system in another machine, I added the backbox kit to MB, as well. The separation between cabinet and backbox now is incredible...you really get clarity in your callouts from the head while enjoying a rich bass from the cab.
I'm telling you...if you really want to add some crisp AND boom to your game, reach out to Dan. Not only is the product awesome, but his service is world-class.