I've never run diff armour, and never hurt my diff, they are not thin by any means but like anything they are not bullet proof either. I've thought about it but it's not high on my to-do list. Now the ball gussets are a good idea, all it takes is one lapse of judgement and you can bend the housing at the very point in question since it is the weak link. The rear housing is fairly strong as it sits and I have never bent one. Most front axles except the 1st few years already have one for the housing, and again the biggest concern is the narrow section right after the bell.