Projector comparisons

thanks for the feedback.  The reason I'm thinking used is that practically speaking I'll only be able to use it so much, and I tend to consider "cost per use" when purchasing anything (or at least most things), thus something like a high end watch, when value over time, actually works out well in this approach.   I'm okay with not having the latest and greatest (though I do prefer) and though I love my Panasonic VT60, I'm sure even a several year old projector will be a completely different experience based on size of picture alone, and I can deal with some minor imperfections.  I notice the higher end Sony's have, according to the reviews, much better lenses and auto features, but don't know enough about this space to be able to adequately balance out those features vs. HDR/HLG, etc.  My room shape may change at some point as well, so a projector that affords setup flexibility is important. I'm also looking for HDBaseT compatibility as the run from equipment rack to proposed projecter site is tricky and will involve a long run of cable. My marantz AV8802A does not support that, but I believe there are devices that can be inserted at both ends.  There's a lot to consider! however I'm not on any fixed timeline so will continue the research. 

@esthlos13 you could also consider a long HDMI cable that uses active transmission (chips at the send and receive connectors), as an alternative to HDBaseT.

What is your budget? Does the 4K to 7K include the screen? Does your room have complete light control? What size and type of screen are you considering? How far from the screen will you sit? These are some of the considerations that influence your decision. AVSFORUM has an active Display Devices section including over $3,000 and under $3000 projector forums.

As a few have mentioned, JVC and Sony are generally the manufacturers considered for a quality Home Theater Projector.

Sony just announced a couple new projectors so you may find some used options for owners that like to upgrade often. I wouldn't go back more than one generation for used and would want native 4K support.

JVC hasn’t released anything new for a couple years but are still favored by a lot of users. I have owned JVC projectors and currently use an RS-JVC 500. It can play 4K and HDR content but is not native 4K as the current RS3000/NX9 - JVC RS2000/NX7/N7 - JVC RS1000/NX5/N5 models are. If I was to upgrade I would go with the JVC RS2000/NX7/N7. I also have a Lumagen Pro processor that adds a lot of cost but can really dial in a calibration and has excellent Dynamic Tone Mapping.

For longer HDMI cable runs consider RUIPRO Fiber Optic HDMI Cable, Supports HDMI2.0b,4K60HZ, 18Gbps Bandwidth, HDR10, Dolby Vision (various lengths from 6m to 30m).

I'm now on my 7th projector since getting into home theater in the early 90's. In the mid-90's, I was feeling flush from an investment that paid off and bought a Vidikron Vision One and Snell&Wilcox video processor - total investment about $100K, plus the cost of a fancy screen. At the time, this was the best of the best. (Fortunately, I was able to see the system at a reasonable price to the person that bought that house from me a few years later).

The Epson 5050UB projector I bought recently for under $3K delivers significantly better performance - MUCH brighter, better resolution, better shadow detail, no convergence problems, lower audible noise, much better uniformity across the screen.

Projector technology is changing as fast as flat screen TV technology. If I was you, I'd invest in a really good screen, since this will last you over multiple generations of projectors. A quality fixed-frame screen will run you between $1500 and $3000. If you want retractable or electric masking, the cost will go up a fair amount. Don't skimp on the quality of the screen. 

I'd recommend against getting a used projector. Not only is the technology changing fast, but you have to worry about compatibility with new content and equipment, and they don't last forever. You'll almost certainly need to replace the bulb in order to get full performance, and will probably have to have it thoroughly cleaned to eliminate the dust that accumulates inside. And you probably won't have any warranty. Given the projector quality you can get for the money these days, it just doesn't seem worth it. For under $3K, you can get a stunningly good projector.

What are the minimum specifications for a laptop to process 4k video for a projector? I am considering new models of high resolution projectors. But I have doubts about the laptop: core i5, 8 Gb RAM, nvidia 630m 2 Gb.