ARB lockers are expensive. That is about it for weaknesses.
Disk brake kits used to be expensive, but not anymore. Plenty of locker choices. Shafts are strong.
One of the biggest advantages is that you don't have to shave the housing like you would/should on a 14 bolt. And they are cheap...
I ran one on my old crawler
Special Thanks and Recommendations to;
PAC Racing Springs
Joint Clutch and Gear