To each his own.For me trying to get much better MPG is just a game. With a hybrid there is minimal cost savings. At 13,000 miles a year and 3.65/gal gas, going from 41 to 48 only saves $168 a year (if that MPG is averaged for the FULL year). If I try really hard I may inconsistently get 45. Without trying I get 42. 45 would only save me $75 a year. The headache and stress of trying to maintain a high mpg is not worth it for me. I do recognize that we all have different variables though.
If I can save $168 a year, merely by doing something that occupies my time and my mind while I drive, I will gladly do it. Where we live, $168 pays 3 months' worth of water bills OR 2 months' worth of springtime electric bills.