Why does everybody use air lockers?

Are there any aftermarket electric ones?

Nope. Too my knowedge the ARB is the only cabin crontrolled locker available for the Xterra.

Rumors are that the 2005 Xterra may offer an electric locker.

but rumors also have it, that it wouldnt fit our X's right?

Nope, not with a D44 rear axle on the 2005s...

I'd like to see the Detroit Electrac available for the H233B, it's an LSD that fully and mechanically locks electrically, but it's not even in the picture. As I recall it's designed for conventional diffs with a rear cover, the actuator is built into a replacement cover. It would be almost starting from scratch to make one for a third-member setup like the H233B. Might be an option for the 05 though unless there's something special about the D44 implentation by Nissan that won't let it fit.

ARB is the ONLY locker, outside of welding your diff, available for the Xterra.