Fixing my brake efficiently?

I have a 2001 Honda civic coupe LX. When I bought the car, the brakes were a disaster waiting to happen. I ended up changing the front rotors, brake pads, and rear shoes. I need new drums in the rear badly, so I was thinking whether or not I should buy new ones, but my question is how much improvement will I receive if I change both the rear drums? Nothing inside where the shoes are located, just the outside drum where it comes off. I would imagine that it would improve the brakes performance significantly, I just want to be sure before I do this, thanks

Drums have a minimum diameter measurement stamped into them, if they exceed that they should be replaced. However, front brakes do 70-80% of stopping, so if shoes are OK, no excessive grooves in drums, they're fine.