He sure has taken a different approach this time. In 2000 he seemed to work shorter days and often skipped the weekends. Of course he has more motivation now with 9-11. He is doing an amazing job in this campaign...You can just feel his energy and sincerity and the people respond to it with enthusiasm.
George W. Bush promised his wife in 2000 that he would find time to be with her at home during the campaign, so he'd come back weekends because he placed a high value on his marriage.
In 2000 he believed he'd be a better president than Gore, but didn't hunger for the job as much as Gore did. Now he knows it is vital for the country that he remain President.
It's easier on him this time with his daughters with him on the campaign trail and his wife with him more.
Also, he knows that Gore working through the night before the election in Florida made Florida close and made for a terrible time for the country, and he won't let that be his fault this time.