Not any more than the CFOP solution, I'm sure. My solution after the triple x cross was U' L' U' L d' L U L' U sexy sledge Ja, for a total of 37 moves for the entire solution, I got an 8.02.
I think that generally, whenever the question of "could some other method be used here" is posed, the answer is "not faster than CFOP." Most methods end up being more useful as add-ons to a CFOP solve anyway than as entirely new methods. Truthfully, at some point the difference between methods with a "last layer" step becomes quite blurred. I didn't even think of my solution as a triple x cross when I planned it, I thought of it as making a five move pseudo double x cross, then inserting third pair, then finishing cross. If I were a top level solver, I probably would have oriented the edges during fourth pair and used a zbll, at which point the solve was basically a petrus solution.
Belt is, to my understanding, basically "redux the 3x3 to a square-1 and then solve it like a square-1 sans cubeshape." Square-1 is already a slower puzzle than 3x3, and you have to spend more time doing the redux than cubeshape, so this doesn't really make much sense.
The only other actually good method is roux.
