I did some tests on the battle pace of Mother 3 and Mother2k3, and here are my results:
Mother 3
4 Characters, 1 Monster
Actions: Attack
Fastest Average Per Turn: 5.1secs
Mother2k3
4 Characters, 1 Monster
Actions: Attack
Fastest Average Per Turn: 5.3secs
Mother2k3 is slower?! Nah, of course not. For Mother 3, I had to use the battle memory so the monsters didn't do anything. The monster in Mother2k3 did attack so that takes away a good second or so. Even if I didn't use the battle memory, the results would have probably ended up around 7 seconds since the message boxes in Mother 3 are pretty slow and also the slow enemy attacks + damage.
So why is this important? Well, for taking advantage of the rolling HP/PP. And... I like fast-paced battles. :D
Note: This will NOT work in the demo because I have updated the battle system. Plus, the demo is greatly outdated again.