So I have a stock 2015 JKU Sahara, and I am contemplating a mod in the near future, but I'm not sure which one is more worth the investment. From a daily driver with occasional light to moderate off reading, would a lift make more sense (don't really plan on going bigger than 35" tires), or installing an e-locker for the rear? Thanks.

 

Do you plan to regear at the same time that you'd do a locker? Do you already have the 35s or those are in future plans as well? A suspension life really isn't going to be some upgrade in performance outside of a little belly clearance. The lift is primarily to accommodate desired tire size, and it opens an entire can of worms that takes a decent-sized wallet to address correctly. In regard to traction control, do you feel like you need it? Do you go out on your own a lot where having additional traction is adding a lot of peace of mind? Have you run across things you couldn't do and where added traction was going to make the difference? Just some general questions. I'd likely lean towards traction control being better bang for your buck than suspension lift.

 

Installed lift kits look cool and make it obvious that work has been done. Traction control goes unseen no one knows its there unless they are riding with you up a steep incline or mushing your way thru mud or snow. Traction control as resharp noted, way better investment than a lift. You can go more places safely with a limited slip or locker than you can with just a lift of some kind. Adding steeper gears while you are in the differentials is also a very good decision.

 

"occasional light to moderate off roading" doesn't require 35" tires. If you're going for looks, yeah, 35" look cool, but requires a lot of retooling of the suspension = $. I went with 255/80/17 pizza cutters, which are 33", a TF leveling kit, and skid plates. With this, I can handle any kind of occasional light to moderate off roading and know I'll be just fine, and it wasn't a big investment.
A locker is great when you need one. Same could be said for a winch.