Varies between airlines. Usually the non budget airlines are slightly better service and amenities but the difference is shrinking. However, the. Udger will have extra costs for everything, including luggage etc. so it depends on the cost difference.
No point saving $20 then paying $10 for luggage check and $10 for a snack.
Generally best to look at what's going to suit your schedule best unless the price difference is enough to change your plans around it. 6am departure can mean a 4am rise. You'll be tired at your destination. 9pn departure, you'll just sleep when you land and need to pay an extra days accommodation.