When I got into this I tht brighter was better for the light output of the projector. Mine is about 1800 ansi lumens - it can be used in a fully lit room no trouble.
Too bright - dazzling even.
I know use the projector on low - 5000 hours bulb life is a bonus - and use an ND2 filter sellotaped to the front of the projector lens to knock the brightness down.
After much set up disc fiddling I can now percieve the brightest whites as different shades and the blacks are nerly proper black. The percieved contrast ratio is much higher and most comression noise is now lost in the dark areas. Everything appears much more ' 3d' and the screen door thing is nearly gone.
If I want to watch in a bright room - and I ususlly dont - I just flip up the filter.