Maximum battery saver works best. However you may see it running slower when accessing applications due to its working to save your battery life. Also was informed it helps because after you are done with accessing an app it closes the app to provide better battery life. You can also visit our site at http://search.vzw.com/?do=viewdoc&id=20102&p=null#b4 for other tips on better battery life.
I currently use nighttime mode and my phone has not needed a charge since I synced it on Thursday. Just play around with the settings according to what you do with your phone to see which works best for you.