Light Leakage
The BenQ W100 leaks a rather significant amount of light out the bottom. If you position it on a table this should probably be a non-event, as I had no problems with that light getting to the screen or "lighting up" the room, to the degradation of the picture quality.
If, however you choose to ceiling mount, and the projector is hanging down, I do suspect you will get a rather noticeable bright area about the projector. I would therefore suggest that you darken the area of the ceiling where your mount is, to minimize any potential problem. (The mount itself is never pretty, so cosmetically, this shouldn't be a real issue.
Audible Noise Levels
It's amazing. The W100 is very quiet. Claiming <29 db in full power, and less than 25 db in economic mode, it is one of the quietest projectors out there. What blows me away, is that I have recently tested several projectors, that are much more expensive (Optoma's excellent HD7100, and SIM2's $20,000 incredible C3X) and they were significantly noisier. Bottom line. Noise is not an issue in either power mode. The BenQ is surprisingly well done for a small, light, bright, and affordable projector.
Projector Brightness
Sorry, more measurements needed, but I will update. I only took one set, that was in the projector's best and dimmest mode (it was getting late, and I was more interested in measuring the grayscale accuracy). The lamp was in low power ("economic") mode, the image preset was in Cinema. I measured 388 lumens. Not bad for a best mode, however in full power that should jump to around 450 lumens, and I suspect moving to Movie mode from Cinema would likely add another 20%. Family room mode was much brighter still. So please, don't hold me to this, but I suspect for now, that in full power, and family room mode, we are probably pushing well over 600 lumens, very respectable. I base this conjecture on watching the projector on my 128" Firehawk where I used only full power mode, but played with all three mentioned presets.
Lamp Life and Replacement
The W100 has one of the longest claimed lamp lives out there. In "Economic" (low) power mode, BenQ says 4000 hours, and even in full power, 3000 hours. It's menu item that reports lamp usage, indicates that it tracks equivilent hours, so that it actually pays attention and factors in which mode you are using. Basically if you run it one hour in economic mode, it records 3/4 of an hour, if you run it one hour in full power, it records 1 hour. As a result, regardless of how you use it, 3000 hours is when it tells you its lamp replacement time. Remember lamp life varies based on many factors, and keeping your filters clean is very important to the projector running cool and your getting maximum lamp life.
When it comes to replacing the lamp, the access is located on the bottom. If you are using the ceiling mount, you are going to have to unmount the projector to change the lamp.
Projector Screen Recommendations
Making screen recommendations is usually about the toughest part of each review, and I'm never fully comfortable doing so. What I think works best is often not what another would consider ideal. Some favor high contrast grey screens (I generally do), others like screens with some gain. Issues such as rejecting side lighting, having some light in the room, and roll off in brightness if you sit off to the side, make one's room and viewing habits critical.
Still, here are my thoughts.
I found the projector worked extremely well with a light gray high contrast screen (my Stewart Firehawk), and it had sufficient brightness to perform acceptably in full power mode on a large screen. However in best mode (Cinema) it could have used more horsepower for my Firehawk (which is 128" diagonal, and therefore larger than probably 90 - 95% of most people's screens.
I also used it extensively with the Carada Brilliant White, at 106" diagonal (and a 1.4 gain) the W100 looked great in low power. However, with that size bright screen the blacks weren't quite dark enough for me. Using the Cinema setting, I found it to acceptable, but even the Movie setting didn't get me the blacks I wanted. On the other hand, I could pump a reasonable amount of light in the room and still get pretty respectable results.
High contrast surfaces are designed to reduce the brightness of black areas, so for a fully darkenable room I would lean that way, but for more of a family room a screen like the Carada (or equivilents from other major brands like Da-lite, Stewart, and so on might be your best solution.
Last thought - HC gray screens are much better at rejecting ambient light from the sides, so if you have a window leaking light on a side wall, or sconces on the side walls, that might be a good reason for HC gray.
Have fun in choosing!
