Has anyone had any problems with the tubes on the non-disco d30 being weak?
If I were you, I'd rather get a non disco d-30, just for the simple fact that you won't have any seal problems when trying to get a one piece shaft to work. And if you want extra strength, truss it.
To me, even with a posi-lock, the two-piece axle shaft is just too much of a complicated mess to deal with. You got an extra bearing inside the shaft, you got more moving parts, and you have the possibility to end up like me, even with a fully working disconnect, it still screwed up and made 4x4 useless.
However, you can always be like me, and get a one piece shaft from a non-disco to put in your disco D30. You have to get an aftermarket seal that fits the diameters and that can be tricky.