As to which method is easier, spraying a ceiling is the winner, as far as the actual application of paint or texture. To spray the ceiling, you aim the spray gun, pull the trigger, and keep the spray moving from spot to spot. If you paint the ceiling, even if you avoid using a ladder and use a roller handle extension, you still must work your arm and shoulder back and forth to apply the paint or texture.
Although it is easier to spray the ceiling, spraying is a much messier method than rolling. Spraying creates a mist of texture or paint that falls down and settles on everything inside the room, including furnishings and floors. Therefore, before you spray, you have to cover everything in the area with plastic or move it out of the room. Rolling, on the other hand, produces only a few specks and drops.
The equipment you need to roll a ceiling are less expensive and more readily available than the equipment needed to spray it. The basic materials for rolling a ceiling are a roller cover and handle, a roller pan and a roller handle extension. You can find these in a local hardware or home improvement store. To spray the ceiling, you must rent the spray gun, a hopper and possibly an air compressor for a day or maybe a weekend. Purchasing these items is far more expensive and not necessary unless you plan on spraying a lot of ceilings over an extended time period.
Especially with ceiling texture application, the texture you roll on the ceiling dries faster than the texture you spray on it. One problem that may arise because of the rapid dry time with rolling it is that the next day the texture may fall down in spots because it is cracked. Because it dries more rapidly, you also have to work much faster, in smaller ceiling sections, if you are applying texture such as orange peel, which requires you to go over the rolled texture with a sponge.