I've had limited slips that slip more than grip, so I much prefer the locker. Traction control works for a lot of street situations, but I'm glad Ford offers a locker instead of limited slip in the F-150 now.

 

Lsd with friction material in the differential or friction material at the brakes makes it the exact same thing. As long as the control module is working.

 

I can't think of a single reason why a 4x4 truck w/electric locking rear axle should suffer price degradation on resale. I'd be more wary of the massive lift, 37 inch tires, etc, etc, If a savvy potential buyer is looking for a 4x4, they will appreciate the locker. Today's lockers are so much more reliable and easier to use than those in the 80's', that decision is a no brainer.

 

FWIW, I opted to go with the 3.15 elock option because I wanted it for pulling my boat out of the water - just in case one of these steep CenTX ramps wanted to be a problem.
(oh, mine's a 4x2)