I pulled those out with minimal damage to the ceiling and discovered that the popcorn (or acoustic) treatment had been installed after the valances had gone up and was not present on the ceiling part behind them. That meant that I would have to build up the treatment to match or remove the popcorn from the entire ceiling.
Since I seem to have a penchant for doing things the hard way, I opted for the latter. Plus I HATE HATE HATE popcorn!!! Popcorn is mainly used by builders because it is so much easier to do than paint. Plus it hides any defects in the mudding and taping of the joints as well as poor workmanship. Did I mention that I hate popcorn??? or for that matter any ceiling treatment?? They seem to be the one thing that instantly date a house. They trap dirt and are generally FUGLY!!!!
So I Googled popcorn removal and the videos and instructions made it look so darned easy. Just spray the ceiling with water and scrape off with a wide trowel. The popcorn drops off and leaving you with a nice smooth ceiling. NOT. My popcorn was mutant!!! I used my floor scraper with a new blade and all that I managed to get off the ceiling was the first few millimeters.
I had to then wait for the ceiling to dry, sand it down with a pole sander with vacuum attachment, skim coat with joint compound, allow to dry, sand, skim coat again and hope that it looks good.
This is a Vacuum Pole Sander that saved my sanity and probably my marriage. The dust gets sucked right into the attached vacuum.
.......and this is the HEPA filter that saved my Shop Vac. Without this, the filter would allow the drywall dust to blow right through and eventually clog. Pricey, but washable and reusable. This is well worth the price.
After all of that work, I've got (half of the surface area at least) a ceiling that is smooth, looks modern and will look amazing painted in Benjamin Moore's 'Decorators White'
However if asked in the future how to deal with Popcorn ceilings, my simple answer would be - Move!! This is not a job for the faint hearted, the lazy or the ones daunted by a Living Room in a mess for the better part of 2 months. Moving just might be less work.