Have you tried simultaneous combat...

...and if so, how did it go?

I'm trying to hammer a simultaneous combat method out with USR, a rules lite rpg, and I'm getting hung up on multiple actions during a combat turn. Specifically with making more than one attack in a turn against an opponent who is only taking a single action.

Anyone who has had any experience with simultaneous combat systems for an rpg I would love to hear about it.