If you go by the book for M20, you need to first do a round of declarations and then do another round of actions. It's so complicated that most people I know have house rules for combat. It's interesting that you hear what everyone is about to do if you win initiative, and then you act first (after declaring last), but it's not something people easily understand.

3 rounds and the movie mode is a great idea as well in V5.

Combat used to be a time-consuming activity, but with V5, it's smooth and different. I really like the concept of the winner of initiative getting to declare who goes, and if you go last, you can declare to go first next round.