IMHO, it is worthy if you need the added torque during your driving conditions and is handy for quick accel and passing. This can also be accomplished by shifting gears manually though.
If you are just chilling fat and cruising along, or in traffic, it isn't really a necessary feature.
I personally just find that it shifts smoother with it OFF and rarely have any need for low line shifts. When I do, my left hand knows where the gear shifter is anyways.![]()