I'd give it 4 or more except that unless you have great upper body strength, something I don't have, you end up using an electric sander to finish the job.

It all depends on the state of your ceiling after you remove popcorn. My Den ceiling needed a lot of sanding as it wasn't in great shape.

Having said all that, it does contain dust from scraping along the ceiling.

Simply awesome! There was no need to protect surfaces from drywall dust, wear a dust mask or any dust cleanup whatsoever! I didn't even have so much as a spec of dust on my hands after sanding a 12x8 ceiling and 4 walls!

There is a bit of a learning curve to use the sander as some have stated the head can flip over on the back stroke. This can be avoided by proper pressure on the sander as well as the right adjustment on the tools air suction adjustment valve.

In regard to a previous posters review and picture of uneven sanding showing lines and scratches from using this sander. This will happen if you are using too heavy of a screen grit and applying excessive pressure. Most tools will do that, so I believe that is not a flaw of this tool but a flaw in the users skill and knowledge of drywall finishing.

Would be great, but as other's have pointed out, the flex point is way too loose and if you sand sideways to the long access the unit flops over and will likely damage the wall. I have not looked at mine but other's have reported that the flex head is held together with rivets - and thus no way to tighten it. Works great on a low wall where you can hold the head but sucks on a ceiling. The only way around it is to sand strictly the lengthwise along the short side. Which kind of defeats the purpose of feathering seams.

The head seems a little larger that most pole sanders as well, so the standard grit screen barely fits. You have to barely insert the screen in one end then flip it over and barely catch the edge of the screen on the other end. Don't know if it's because of the greater thickness of the head with the vacuum pickup slots or not. It seems to hold alright, but I would like to have the screen fully seated like regular pole sanders.

There is ZERO instructions on how to use the vacuum regulators on it. If it sucks too hard you need to rotate the little rings to expose the little slots in the vacuum tube and therefore lessen the amount of air being pulled through the head. Not hard to figure out, but not too obvious either.

You also must have a handle to use this, even if you're sanding at a comfortable level on a wall in close quarters. A regular 14" paint roller extension works well in this situation.

As far as usefulness, it works well. Before when I used a manual pole sander it of course left dust all over the place. This picked up close to ALL the dust.

If they fix the sloppy flex joint, make the head so that a standard screen fits better and rewrite the instructions this would be a winner. Until then either spring for a much more expensive pro tool or put up with it's foibles.

I have done the dry wall in two homes in the last 10 or so years. Typical 1,500 square foot homes. I'm currently dry walling a two car workshop. About halfway through, I became fed up with finishing every day and cleaning up for 1 hour and looking like a ghost. I did some research and decided to get this unit. It is so good, I stopped after about an hour to write this. I can not overstate how effective this is. I have a large shop vac, with the paper bag inserted. A typical 5 gallon one I believe would be fine. I am not kidding when I say 98% of the dust is gone, maybe all of it. It is slightly awkward to use, but I quickly learned some techniques to overcome it. This thing rocks!!!

As much as drywall is no fun, this thing is incredible. Sanded, sanded and sanded and little to no mess at all. Yes it is a challenge to do ceilings, but those are tough anyway. If you get yourself as high as you can, you can get the proper leverage to do the ceilings. I had removed 400 sq ft of painted popcorn ceiling (that is worse than drywall), re-mudded some lines and then sanded. I didn't really even need to put plastic up in the doorways. Just surprised at how well this thing really did. I have it connected to a 20 year old shop vac from Sears and it worked incredibly well.

Well worth the $25 I paid. Holds screen very well also. Like that it swivels under a rubber boot also.