The thing about lockers, especially the automatic lunchbox type, is that they add a large amount of stress to the axles.  With the open-diff setup the likelihood of snapping an axle at the spline end and ending a day of fun is much more remote.

Also, in Oklahoma most trails are rutted and rocky with large mud holes, and loose dirt covered hills.  I often get by with a good line and a little bit of momentum.  In addition, the Super Swampers have helped immensely for that simplistic approach.  It would likely not work as well with a street focused tire such as a radial MT or AT.

Now, if I was taking out this rig to someplace like Moab with its long stretches of slick rock, I would definitely have lockers front and rear.

I would never put lunchbox lockers in a Zuki.  Zuki's are too light, and with the fine line in correct setup and driving style changes, they are not worth the disadvantages (IMHO).
Lockers are an asset, but more important is learning how capable our rigs are, and how to wheel them.  And with the number of yours and time you have been wheeling, you are more proficient than I am.

I participated in another trail clean up run yesterday. I think I am going to keep Diablito like this. No doors, targa and when the weather is nice, I'll pull off the windshield (quick release mounts).  For when the weather is a little damp, I'll just throw on a Breeze Top fastback bikini.  If it is cold and wet, I'll just drive another Samurai.

I also ran the tires down below 5psi. Talk about a smooth off-road ride. 

still looks nice even without the doors and targa. any plans of doing some paint job on it?

Yes, I plan on painting it this year.  It will be a medium gray color, and I will likely paint the wheels red. 

That's a great looking old Jeep there in that pic and the paint colors work well together.

Yes, I love the old Willys CJ2 & CJ3 models.     To me the Samurai is just an adaptation of those old jeeps with a more modern (lighter and efficient) powertrain.