Keep in mind that a 10" sub of equal surface area and motor strength from various manufacturers will produce roughly the same amount of overall or average energy. You cannot cheat mother nature and bend the laws of physics. But here is the difference. One manufacturer can produce more energy over a narrower bandwidth or less peak energy with more linearity and extension over a wider bandwidth. Again, the total energy is the same. It's just in different places. So if you listen to bass created from real string instruments you might be disappointed with the SPL speakers that impose their own characteristics on all bass instruments and bass tones. However, if you listen to strictly rap and electronic techno, there may be few string instruments with more of a monotanous bass beat generated by a keyboard, synthesizer, laptop, etc., none of which are real instruments. For instance, there are many videos showing the water jumping around the hull of the boat and in each case the bass sound is totally indiscriminant.
So importers like RE and Sundown take off-the-shelf China parts to make a speaker that is focused on one thing for one type of listener. A paper cone in this day and age is kind of a give away.
While not for me personally, these type of speakers are exactly what some people want and those are the people usually populating the DIY and car audio forums.