Just noticed this now...
My best description is it makes bass seem louder than it really is. With a small, weak, offbrand 10" sub, it really *seems* to have a lot more power than it should. Basically, the theory is bass is mostly felt and not heard, so they make you feel it more. The 10" fills in what you hear.
I would say it does a pretty good job, overall. I thought it was a stupid thing at first, but after trying it, I have to say, it really does trick your mind into thinking their is more bass than there is.
I have been happy with it. I have one, and right now it is behind the center console on the floor. It is surprisingly powerful for where it is.
To answer your original question, I think if you dumped the 10, for a hidden 8, and had a bass shaker, it would be at least like you still had the 10 there, maybe even a 12. The best part is, though, it doesn't leave your ears ringing.
The only downside is whatever they are paired with must still produce a clearly audible bass tone, aka, more than just stock speakers.
Edit: Wow, run on post..
