I'm ok with night out too.

As far as travel, day is easier because foes can see you at night when you can't or can only barely see them.

Not really any noticeable difference, all I know is Random encounters of (Prior to Dawnguard) Volkihar vampires only come at Night

those specific ones most likely still only appear at night, but it's a bit confusing when you have Dawnguard and a ton more vampires get added to the bunch that randomly encounter at any time.

just my personal preference, I like Daytime, specifically Early in the Morning

Noontime shadows annoy me for some reason.