I have a gently used BenQ W5000 with 2 lamps (I with aprox. 1600 hours and the other with aprox. 800), purchased directly from BenQ during their refurb sale a couple of years ago. Always ceiling mounted in a dedicated theater room in a smoke free home. Due to error by BenQ by sending me an initial unit with a broken focus ring, I was able to eventually select my unit out of 3 presented. Ironically enough, the one with the broken focus ring was the quietest, sharpest and most uniform in light output and was sent back to BenQ for repair and firmware update. I've extensively calibrated this unit (check out the BenQ W5000 thread here at AVS) with ColorHFCR and an Eye1. I am not a professional calibrator by any stretch of the imagination.
The only issues I've had is the normal (at least normal for BenQ W5000) 'lamp failure to strike (about 6 times)', turn off and wait 15 minutes and start again.
Some W5000 owners are reporting some sort of failure with their projectors that cause half the screen to fail with thin vertical lines of the image frozen on screen. I've noticed that when my W5000 either syncs to a source and/or changes resolutions, I see during the sync process a break in the image down the center and wide vertical stripes with image corruption for 1 second or so. This projector has always done that (as did the other two I sampled as well).
However, about 6 times since I've owned this projector, these wide stripes of corruption have stuck on screen after syncing forcing me to shut down and restart the projector. This anomaly has never happened again after a restart, but it has happened more often recently, I would say 3 times in the last 6 months vs. 3 times for the previous 1.5 years or so. It has made me question if it is the same problem others have reported. The only difference is the vertical bands are wide, maybe a dozen on the right half of the screen (ceiling mounted) where all the images I've seen posted had skinny vertical stripes of maybe 30 or more on half of the screen.
So buyer beware! Other than what has been described, this projector throws a fantastic image, is quiet (relatively so as I now have an RS40, purchased during AVS's B Stock sale, and it is REALLY quiet), and trustworthy. I hate to see it just sitting there when somebody could be enjoying it. I am not sure what its value is and am willing to accept offers. If you have any questions or insight into the vertical stripes of image distortion, please PM me.
Oh yea, the projector is blemish free and I believe I have the original box as well as remote and manual and numerous extra filters.