Is the overdrive supposed to stay on all of the time on a 2005 Hyundai accent?

I have a 2002 Accent with the overdrive button. The owners manual suggests that the switch should be engaged to have overdrive on all the time. However, I have found that since I do a great deal of stop and go driving the transaxle shifts and performs better with the overdrive off. The car isn't trying to put itself into overdrive every two seconds and makes for a smoother drive. Again this is mostly for heavier stop and go driving.