Dive machines, because of the wide trains, cant do that much in the way of elements becasue the trains would stress too much due to the rotational forces on the ends. The forces would also be too high on the riders on these seats. Things like zero-g rolls won't be possible, no tight and snapy inversion would be, unless the trains were smaller.
I am not 100% sure I am correct in this, but originally, Oblivion was meant to have 6 across, but that was made 8 for a better capacity, so I can see a smaller version of the dive machine doming out using 6 across. 6 across would also mean less stress on the ends of the train, and because it is shorter, it can go through tighter elements.
The two American ones are similar becasue they are both owned by the same company, and the Asian ones are similar to them because they have a thing for copying rides.
Dive machines are long from dead, but they do need some sort of inovation to make sure they stay that way.