My dad managed to roll the bottom-half of the ceiling with his 8'-16' extension pole, but it would have been a real struggle to get clean coats on the upper-half without the scaffolding. Not to mention the ease of trimming out the corners and edges while standing on a flat surface (instead of having to balance on a ladder and then going up and down it a million times). I almost stepped off of the catwalk a few times (I guess I was REALLY getting into the painting), but luckily managed to avert any major disasters! We easily got two coats on in one day and were able to return the scaffolding later that evening.
We didn't finish all the ceilings as we had originally hoped. As we were removing the old flush-mounted light fixture in the guest bedroom, a piece of the textured ceiling came loose. In fact, it just peeled away with very little effort. We debated about what to do -- patch it or remove it -- and finally decided to try and remove all of the texture down to the original drywall. We used putty knives and I would say that 90% of it peeled off with little effort; BUT the other 10% was about as tedious as it gets.
And I don't even want to think about the heavy "starlight" texture on the ceiling in the office. We still haven't figured out what to do with it; but that's for another post.