Are IC2 Reactors or Extreme Reactors more efficient?

Hello, I just got back into playing modded minecraft. Since I have been gone Big Reactors/Extreme Reactors, from what I can tell, have become pretty mainstream in packs. Before I start working on long term power solutions I was trying to see which mod creates the most power per resources and any other factors. Extreme Reactors seems simpler but I'm not sure if it trades it's simplicity for production. What have you seen from your experiences?