Others say...

"easier than expected"
I'm not the handiest guy and expected the mounting process to be a chore. However, I had no issues whatsoever. This thing comes with many different screw sets and one set exactly matched my Mits HC1500. From that point on, it was a piece of cake. It's very stable when locked in position. Occasionally the projector shakes, but that's only because my kids are jumping around and shaking the floor upstairs which vibrates the basement ceiling beam on which it's mounted. (A quick shout upstairs usually solves that issue.)

Also, I had to exchange the projector once so I went thru the mounting/unmounting replacement cycle and had no issues whatsoever. Overall a great product.

"Works fine"
Plenty of extra arms and spacers to fit almost any size projector. Went up easy without a hitch and is flexible to adjust to any angle. Doesn't drop down from the ceiling too far either. My Optoma is smaller so I don't now how it would work with a large projector but it might be a little wobbly with extra weight.

"Almost just right"
This mount fit my Mitsubishi HC1500 perfectly. It had all the hardware I needed and a very generous amount of extra hardware, enough to adapt it to any projector. It is adjustable 360 degrees around, about 90 up and down, and side to side a couple of inches. It was easy to install. The only downfall is that I didn't realize it was white and I would have preferred black. My fault.

"Semi-difficult to install"
I've only used this for my one projector, a Mitsubishi HC4900.
It comes with four legs to attach to your projector that can be moved to almost any position. To bolt do the ceiling the unit comes with two different bolt types, one for straight into the support beam and the other for drywall.

The only part of this that is really difficult to operate is that the unit separates into two sections, the one that attaches to the projector and the other that attaches to the ceiling.

To start you attach the ceiling mount to the ceiling and then the projector mount piece to the projector. At this point is where I found it semi-difficult to install. You have to lift the projector above your head and insert projector mount into the ceiling mount and then hold it there while you screw it down. It almost requires three hands, and I had to use my head to stabilize the projector during the process. My opinions is that that could have been easier.

Also if you wanted to tilt to the left or right, up or down, I found it easier to grab the project mount and pull rather than loosening the bolts. Loosing the bolts was extremely annoying.

All said and done, it works. I'd give it a 3.5 rating if possible, but in the end it was easy to use and I feel secure in it's installation.

"Came Fast and Worked as Promised"
Bought the mount and it came within a week. It comes with extra arms of different sizes to ensure you can mount your projector and I actually HAD to use the smaller arms it came with. I 'could' have gotten it to work with the longer arms but the convieniance of the smaller arms mades this a 5 star product. Plenty of hardware to get this mounted, including a cement kit so long as you can drill into the brick/cement and know how to use the anchors.