INTROClosest thing I've had to a theatrical cinema experience in my living room. Amazing detail, depth, a visual sense of presence, and exceedingly broad color and illumination range.Probably most buyers will be happy to bring it home, mount it on the wall, maybe add a sound bar (though its built-in audio is also quite good) - and you're all set. The smart TV web interface is sophisticated, regularly updated, easy to use, supports numerous sources and channels for viewing and streaming. (Pop some popcorn, and you've got a theater.)Then there are TV geeks (like me) who already own an audio-visual receiver (AVR system) that ties together external devices as program sources. If you are one of these, well, that's what most of my review touches on, a geek project of replacing a 1080p TV with this LG G3 4K system - and keeping the rest of the home theater intact. I also mention a great buying experience, what a beautiful TV the LG G3 is, and using a mount stand rather than a wall mount. Here goes.BUYING and VIEWINGExtraordinary, beautiful display that continues to exceed expectations, every day. Selected the 65" LG G3 based on over-the-top, expert reviews. Currently watching standard antenna TV programming - which looks greatly enhanced - and where LG G3 truly shines, watching 4K Dolby Vision and HDR10 programming. (In my home theater, 4K input sources are external devices: a Roku Ultra streamer and a Panasonic UB9000 4K UHD player, supported via a Denon AVR with B&W 5.1 external speakers. But again, many others will prefer to use the LG G3's own smart TV WebOS interface as their programming control.)My Oct 2023 Amazon delivery was terrific, using a pre-arranged date/time, safely delivered under my supervision into the front interior of my home by two delivery techs.INITIAL SETUPI chose to uncarton it myself. A 62 lb. large TV is beyond my guy grip for carrying so I safely slid across carpet to an initial test spot, where I vertically secured it at sides plus front and back using sturdy furniture, buffered by safety pads. Since LG G3 has control buttons on its underside, midpoint of screen, I raised it off the floor at both ends, to not put upward pressure against those control buttons during temporary setup.The G3 comes with a wall mount - but no TV stand. You'll likely choose to wall mount or else buy a beefy TV stand. With my older home's plaster walls I chose against wall mounting, going instead with a heavyweight TV display stand resting atop some existing media furniture. Despite G3's slim profile, it's still a sizeable, substantial TV that requires a very solidly built, robust TV display stand if you use that method.My first TV display stand pick was LOUSY for this model: the PERLESMITH "Swivel Universal TV Stand for 37-65,70,75 inch" (‎PSTVS02) uses a 25" wide backplate, so wide it obstructs the 65" G3's rear coaxial antenna port, contrary to PERLESMITH's product descriptions. I phoned PERLESMITH's support number to ask if they can send me a shorter backplate since 25" was too wide and really, far wider than needed for the 65" G3. They had no solution for me. Had to give up on that stand.Then I chose the excellent PERLEGEAR (not PERLESMITH) brand "Swivel TV Stand Mount, Universal TV Stand for 37-80 inch TVs" (‎PGTVS28) from Amazon with sturdy, width-adjustable backplate. Its 99 lb. rated capacity exceeds this 65" TV's own 62 lb. requirement. The stand's swivel feature also nicely adapts the viewing angle for my movie guests. A clean, beautiful, modern design stand.Raising a 62 lb. TV and 17 lb. display stand onto media furniture is a two- or more-person task so I hired a handyman skilled in home theater gear for a few minutes to assist, after I'd fully assembled and tested the stand and its locking mechanism for holding the TV securely.DAILY USEI'm addicted to daily viewing this fine system. Viewing local news and saying, "gosh, I've never noticed how many strands of hair my TV meteorologist has" or to continually admire the vastly greater variations in individual colors rendered to the screen - that's the starting point where we say, "this is more like being there, than any TV I've had." And when its 4K support instantly recognizes a Dolby Vision or HDR program source and auto-switches G3's display mode to the matching display standard, and when the purity and vibrancy of inky blacks and bright lights mimic what we'd see in person on location or at a film stage - then, yes, we have an immersive, oftentimes "jaw-dropping" experience.REFINED SETUPExpect to make some setting tweaks as you would for any new TV - particularly if you use external devices. Many home theater enthusiasts with multiple program sources and an AVR will be accustomed to tweak settings at the display, some at the AVR, and to a lesser extent the external devices - generally fine tuning at the higher-end (display, AVR). I tuned my LG G3 display modes by hand without a reference disk (amateur here, though with some years of experience). Then selected my preferred auto display modes for when Dolby Vision or HDR are detected, and for standard non-4K sources. With tons of published tips online for tuning, I won't try to support that detail here. But expect to get to know your equipment. Have a tech help you or study, learn, and tweak settings "DIY" as desired. And have fun!A valued reviewer on this page discusses a feature that challenged me, too. LG's implementation of HDMI-CEC is called “SIMPLINK” and can be enabled to use ARC to:• (A) Send G3's audio output to an external sound system - AND -• (B) Use G3's remote to control external, HDMI connected devices.I wanted choice A without choice B. (I already control existing HDMI connected devices from my AVR plus a universal remote. The AVR gives me matching audio output to external speakers and matching video output to my TV.)LG G3 SIMPLINK seemed to insist I must use both (A) and (B). That bickered with using the AVR, instead, to integrate and control external input devices.Since I couldn't get SIMPLINK to give me (A) without (B), I completely disabled SIMPLINK.Then, for (A), outputting G3 audio to AVR and external speakers, I ran a TOSLINK optical audio cable from G3's TOSLINK audio output port, into the AVR.The TOSLINK standard supports up to 5.1 audio and works well for using G3 to view antenna TV, or G3's WebOS web channels, or G3's WebOS media player for USB connected photos and movie files.If you experience device control conflicts between SIMPLINK and an external AVR, search AV forums for a best solution for your use case. This was a headache for me for a few early days - again, resolved in my case by disabling G3's SIMPLINK feature and disabling ARC in my AVR.Be willing to make home theater design choices. Placements of system, speakers, seating, lighting. And if you use an AVR as your main control, your setup will differ from using LG's fine Smart WebOS as your main control.Since I swapped out an older smart TV (whose "smart" interface I stopped using after its publisher stopped updating it), I wanted my new 4K display to behave as that prior TV: a display device rather than as an activity hub. For streaming I also preferred to keep using my external Roku streaming device as a "modular" component since it excels visually/audibly and since I already had my streaming subscriptions programmed in and authenticated. This also saved me from manually reconfiguring all streaming sources and user credentials into the LG G3 WebOS. This called for tweaking some LG display and AVR settings, swapping in a couple of upgraded HDMI cables for 4K support, and in my case optionally adding a 4K UHD Blu-Ray disk player. Your mileage - your design - will vary.A "gotcha" when using external HDMI devices: switching program sources can trigger a temporary black screen and a brief LG "no signal" message as frame rate and settings promptly recalibrate to match the new 4K input source. (The brief interruption sets up the new 4K program source for optimal 4K presentation.) Viewing then resumes normally, with G3's spectacular output.Hope this helps you shop! Enjoy your new TV!