I have a small room, with 2 windows behind the roll up screen, Beamax white with 1.2 gain about 90" diagonal. The HW10 is as close as it gets to the screen, used in wide mode for maximum brightness. There are wooden shutters outside that can close out just about all light, but so far I haven't used them. Just closed the curtains, which leave quite a bit of light in from streetlights right outside.
The room is far from ideal: whitish ceiling, white walls, a bookcase with glass doors, and 2 large frames also covered with glass. And a light brown wooden floor. In other words, light loves bouncing around in it.
When I watch a movie, there's enough light to read a book by. Most of it is light reflected from the screen and then bouncing around in this light room.
In these circumstances, I find the PJ in high lamp mode just bright enough, but wishing for more anyway. Problem is, with more light hitting the screen, more will reflect around the room, so I don't think a light cannon will make any difference. I really would need a darker room setup, but that's not an option unfortunately.
There's not much difference between the various settings as far as brightness is concerned. Low lamp mode visibly reduces brightness and the image loses its punch. In my case low lamp mode is unusable.
In your case I would estimate, if your room is dark in color and you have the same or marginally larger screen size, you should be OK. But if your room is light colored and or you're using a much larger screen, I would find the HW10 too dark.
I'm waiting for my calibration disc to arrive, I read that calibrated the brightness is actually a bit increased. For the rest I'm quite pleased with the HW10, good sharpness, fine panel convergence tool, which should be part of any three panel PJ, dust isn't ever a problem, very silent, no disturbing picture artefacts, nice colours, good blacks and contrast considering the environment.
Can't really complain about the PJ, just about the WAF of a dark room