Is it worth buying a locker?

Bingo! This was the major flaw in the ELocker design in the offroad. Push the button: the ARB is engaged. Push the button again: the ARB is disengaged. No computer nanny shutting it off at some computer set speed.

 

My suggestion..
Try the truck off-road and see how you like the newer TRD Sport works.
If you don't like the functions of the newer Sports, do the yellow wire mod. (trac in 4lo)
If you still don't like the 4x4 capabilities of the Sport, then YES, get an ARB.

Myself and my offroading, the Sport serves me fine. I live in the sandy south, so my offroad consists of alot of sand and mud. I make sure i air down tires, drive smart, carry a tow strap and (for the time being) offroad with someone with a winch, which is something i plan on buying in the future.

 

I thought the yellow wire mod doesn't work on the trd sport?