I didn't answer your actual question, but if you want me to...
The reason you don't see SPL competitors (generally) with sealed enclosures is that to create the highest in-cabin SPL possible, you need to find the enclosure that is the most efficient in that install. A sealed setup of reasonable Qtc is not going to be very high in efficiency...so good luck getting comparable SPL's. The money and time required for each are going to be very different.
Your question has no value in the real world, because the amount of effort getting a 150dB with a sealed enclosure is vastly different than the effort to get that number with a ported enclosure. And even once you've gotten that number, go back to the fact, not the opinion, that 150dB of subbass is simply noise.