And no Chevy or Ford uses a D-30, so I expect it will be a long time before an Eaton is available for the D-30, it ever.
JohnJohn and I both have T-lockers in our 30's and 44's. My axles are not installed in the XJ yet. My only comment about them is that the pneumatic switch they send is large and awkward and difficult to mount. JohnJohn mounted his in the storage space in the console. It would have made far more sense to send solenoid activated switches like the ARB. I like the T-locker because it uses an external air activated solenoid as opposed to ARB's internal activator. However, the T-locker's activator is an obscure German solenoid, and I've yet to source an easily and cheaply available replacement. It's also hanging out there just waiting to be smacked. The 44 cover has provisions for a guard, but my 30 cover doesn't.
JohnJohn has used his T-lockers in Moab and had no problem. They do look and feel sturdy and well-built. I had to remove the cover of my D-30 to replace the seals after the locker was installed. I probably pried and forced it off wrong, but the locker fork(Very similar to the front disconnect forks) broke a chunk off of the ring that it rides in to move the locking pins. I don't THINK it will effect the function, but still, for the price it's irritating.
I really wanted electric activated lockers. I like wiring much better than tubing, but there seemed to be little likelihood of an electric locker for the D-30 becoming available any time soon. We got a pretty good deal by buying 4 lockers at once, so I went with the T-locker. The amount I've spent putting in a multi-purpose air system has sorted negated that advantage. :laugh3:
If you can live with one locker, and have faith that Eaton will have one for the D-30 soon, I'd go for the Eaton. I don't think they had one available for the D-44 when I bought the T-lockers, at least not that I knew about.
Just another .02.
Fred