The BenQ HT5550's placement flexibility is very good. It has a generous 1.36 ~ 2.18 throw ratio, which works out to a 1.6x zoom, and a near-best-in-DLP-class 60% +/- vertical and +/- 23% horizontal lens shift. There won't be many setups the HT5550 won't be able to accommodate.
Art's note: There are some limitations in terms of placement, despite offering far more flexibility than any other 4K capable DLP projector near the price. Consider: The 1.6:1 manual zoom lens provides a lot of placement range, but, it is very unlikely that you will be able to place the BenQ far enough back to sit high on a rear shelf, a feat many 3LCD and LCoS projectors have no trouble doing because o 2.0:1 or greater zoom lenses. A couple of those do cost less than the HT5550, but most cost from a little to a lot more expensive.
The other limitation is that the lens and shift are manual, not zoom. That means no Lens Memory. This is a projector likely to be ceiling mounted, and that means no option to own/use a Cinemascope "widescreen" (like I have in my theater). To switch back and forth from Cinemascope to HDTV's 16:9, you would have to get up, manually adjust the zoom, manually adjust the vertical lens shift (and maybe refocus). Now that might work if you are 6 foot 6 inches and have this projector mounted to an 8-foot ceiling, but, at 5 foot 8 inches tall, I need a step ladder to reach the controls of my ceiling mounted projectors (8-foot ceiling). Definitely not practical to go widescreen.
The HT5550 sports TI's newer .47" 4K DLP chip. This eliminates the dreaded gray border of last year's .47" DLP crop. This chip has a native 1920x1080 micromirror array that uses a 1080x4 ‘wobulation' to put a 4K image with 8.3 million uniquely represented pixels on the screen. The result is impressive and among the sharpest, I've seen from these 1080p ‘shifters'. It also carries on the HT3550 tradition of natively handling 24hz content. No 3:2 pulldown here through a bit of ingenuity on BenQ's engineering team. Motion is very smooth.
Good brightness and better than most contrast are key abilities. I was pleasantly surprised to get 1,400 lumens in a mode you can leave it in 100% of the time. Contrast is also decent for a DLP with help from the onboard dynamic Iris. While not inky blacks like a JVC or even the recently launched Epson 5050UB, contrast, and black levels are well above average for the 4K DLP crop
Other bits you should know the HT5550 include full 3D support, USB firmware upgradability, CFI capability in both 1080p and 4K and HLG support for streaming HDR online. (Art's note: Epson's major competition, the HC5050UB does CFI on 1080 content but not 4K content)