When do I use my rear lock dif

I'm new to a 4x4 truck I have a 04 tacoma TRD 3.4l I'm going to do the grey wire mod but I've heard all kinds of opinions on when to use the rear locker is it ok to use in the desert in 2wd for higher speeds some say ok some day it's bad for it please tell me your opinions and stories off road thanks

 

Use it only when you need it...nuff said

 

Lockers are needed in low-speed low-traction situations. Not needed at high speeds when traction is not a problem. Besides, I think you could break it if you engaged it at high speed.

Disclaimer: I have no experience with the Toyota e-locker, but I did have a non-selectable Detroit Locker in my old rockcrawler.