BenQ TK800M 3000 Lumens 4K UHD Home Theater Projector w/ HDR & HLG Expired

I don't want to spark any flame wars, but I'll take a bite at your questions.

1) You're right that the darkened room is the initial critical factor for many projectors. The comparison vs lcd/led will depend on a few environmental factors, including light control, screen material, and both projection and viewing distance. Viewing position can also come into play as the reflective angles of the screen and projector need to be aligned correctly. If setup correctly, and viewed in a properly light controlled environment, IMHO you can produce the same level of detail from a projector or fixed panel display. But don't underestimate the impact on black levels of light control. Even with a darkened room and cheating via light absorbing borders (like black felt) surrounding the screen, small amounts of ambient light can really impact a projected image. On the other hand, you can't reproduce larger image sizes for anywhere near the cost of a projector, and the visceral impact of that large image (or a larger group viewing space) is a factor to consider as well. For what its worth, I love projectors, but when the price on ~106" panel with good quality and performance drops near $2k I'll buy that in a heartbeat. So far none exist, and thus I'm a projector guy.

2) This answer largely depends on your screen, your wall finish, and the projector (in that order). IMO that can only be answered by trial and error. Note that you can address it by adding DIY panels to the "risk areas" if needed.

Basis: I've used a series of projectors as my primary display for household viewing in an open-layout living room for the past 20 years. All front projection, all at ~106" diagonal, various screen materials and various types of projectors ranging from $500-$3200.

For a dedicated, light-controlled room, you don't want this projector. The TK800M and TK850M are intended for multi-use rooms with significant ambient light. They had a white segment to the color wheel (RGBW) to increase white lumens, which sacrifices color lumens, color accuracy, and contrast. It's a good projector for a living room, but not for a dedicated theater.

The HT3550 is a much better choice for a dedicated theater. I would definitely think it's worth the extra, and you can get a refurb with a full warranty from benqdirect for $1199. It adds more lens shift and zoom, excellent factory-calibrated color accuracy, a dynamic iris for scene-by-scene dynamic brightness and contrast, and 18GBps HDMI for 4K 60fps HDR. It is a very large improvement for the price difference.

A few years old model. 850m is the replacement