No need to feel sorry. ^^
I like this explaination very much. And if someone doesn't like the Abramsverse, just take the Kelvin out of the equation and still there's the XCV-330 left to support this theory.
Regarding the TNG warp core design, I also figured that Starfleet may have developed a kind of coating for the reaction chamber that converts the neutrinos created in the reaction into usable energy. Before that, they had to use these giant TMP style swirl chambers to produce enough energy.
And now, with the ability to use the neutrinos too, the reaction chamber could be much smaller with the TNG design.