Given the choice, I'll take evening hunts every time. Morning's are tough to get in undetected and most good bucks are already back to bed by sunrise and if they aren't the are somewhere that is pretty safe for them.
The rut, late Oct and Nov, yeah get out anytime. If you have 20 minutes, get out there.
Unless you have a solid entrance and a super wind, mornings can do more harm than good.