I guess our bodies all work differently, but for me, travelling East Coast USA/Canada to Europe, it's really a no-brainer - especially if I'm flying in Economy.

A night-time flight means a fitful 5-6 hours trying to get some sleep in an aircraft seat, before being woken up at something like 2 or 3 am body time. You arrive at your destination early or mid morning their time, too tired to function properly, but not really able to sleep either because it's daytime and it's light and you've got all the daytime noises around you.

A daytime flight, on the other hand, just means getting up early on the day of travel and having an early night when you get to your destination. Arriving from YYZ on the daytime flight (a regular journey for me) I get home at midnight UK time, spend perhaps an hour opening post and generally settling in, and go to bed at 1 am my time which is 7 pm Ontario time... slightly earlier than normal bed-time, but not by much.

After a daytime flight home I feel perfectly fine the next day (except that I usually wake up slightly later). After a night-time flight I feel "not quite right" for several days after.

As for wasting a day... there is nothing I like more than having a quiet day, without interruptions, to catch up with some work, compose some personal emails and do a bit of reading.