i thought id chip in, i have the(massive) Benq W5000 projector, had it for almost 3 years on the same bulb and a replacement bulb is only £150 !
got benq to flash the firmware, had it calibrated and the image is stunning! you would expect a big screen to ruin the image, but on the contrary it looks a million miles in front of any plasma or lcd ive seen.
why? because the image just hangs there in space, its not 'backlit' so there isn't the glow that can hurt your eyes, its colors are deeper and more saturated than lcd (hell theres color on there than my monitor cant do)
being a DLP there is no motion blur (takes getting used to after watching LCD) and the image on mine is 85fps (85hz) rock solid and very detailed.
i only run an 84" screen but unlike an LCD your pretty much getting the pure image cast digitally onto the screen with no physical restraint like panel type and response on an LCD.
input lag in less also.
just spend over £1k on a decent 1080p PJ and make sure its well proven and tested. also do yourself a favor, budget a PJ mount compatible with your projector and specify the right length cables i had problems with my 12 meter HDMI yet 10 meter was fine and all i needed.
get the room in shape (many create a bat cave or paint the walls darker) mine are actually light blue and i have no light control in the day its still ok and at night its pretty good but if im honest i know it can be sensational if i got it into a dedicated theater room.. which is what im working on now
keep an lcd tv for the times you dont want to fire up the pj.
btw LED PJ`s are the future, it will take time for them to mature in terms of color purity and temps but given time these units will change how people watch tv as they fire up instantly, and do 30,000+ hours on a single bulb ! also due to 3D next years projectors are going to have to be around 3x as bright :O and 120hz compatible ! so there are some really good 3d times ahead but more so, some really amazing 120hz,120" 2D pc gaming times
