To be perfectly honest, the reasons I changed to a B-210 rear axle were, 1) I had one and b) slightly bigger drum brakes. That diff survived with (poorly) welded spider gears for years behind my Z-20 engine. I've never had a diff break, or even know of anyone who has. I think there is a lot of "bigger is better" mentality out there which is really unfounded.
Oh yeah, I just remembered, I swapped a 200SX axle into the Chickenhawk recently. Once again, it had disc brakes and I had it on hand.