How much advantage in adding rear disk brakes?

Maintenance is easier but I don't think drums are bad in the first place. There is much more surface area than disc brakes. I may be wrong but I think the biggest difference is in the driving feel because disc brakes don't retract as much as drums so the pedal feels tighter?

I have a 54 chevy 210 that I left as drums but removed the old brake pedal and under the floor master and installed a firewall mounted power brake booster and master. I reverse engineered the pedal assembly from pictures I found of a kit that is sold and was able to do it real cheap. That heavy beast will stop on a dime now with hardly any effort. It feels like a modern car.