The new technology seems to be in the tip.... Mezz has a white fiber pad and Predator is using a black pad... I think these are both adding a small amount of trampoline effect to the tips....
Taper comes in depending on the type of break cue you want... If you want a break cue that allows you to press control the break at speed you will want a lower deflection shaft with a high kick point.... You want a squat break like Shane you will want a stiff shaft with low kick point so you can jump the ball to the rack.....
As far as jump break.... Most are suitable to the Shane break and not to the press break........