I always take the daytime flights if I can make it work, but I think it depends on your own personal perceptions of what you prefer. I would always prefer a good night's sleep on an actual bed if I can, so I avoid red-eye and overnight flights whenever possible (even with flat beds and business class!). For others, a lost night's sleep isn't a big deal, and they would rather do that than "sacrifice" another day.
If I don't sleep well, the day is a loss anyway, so...