I'm registered at raceacademy, but you can post at radiocontrolzone if you want.
I personally don't understand why the plastic hexes should prevent the axles from breaking?
I think, it's just the other way round, because the plastic ones will slightly deform when cranking down the wheel nut, so they will add axial preassure to the 2x10mm shaft that itself will transfer the load to the axle where it's thinnest making it even more prone to breakage.
But again, I didn't have a chance to try the plastic hexes because they were missing - that's just what I'm thinking from a mechanical point of view.
To Lotus1
If you're just bashing, do yourself a favor and get the Academy RT-4 Gear diffs, 2x RG039 and ST-17 and ST-18.
The academy ball diffs are good, better than the old Losi XXX ones, but at least they do not have the durability of a gear diff.
You won't need any spacers for the rear dogbones when using gear diffs.
As for the ball diffs, the springs are not good, to much axial load and binding!
Instead, cut an ear plug to an appropriate lenght and stuff it into the outdrives (will make a nice dust cover for the thrust bearing btw
)
But remember, you never want the ear plug foam to press against the dogbone! It should just prevent it from falling out.