Was fortunate to find an old CRT monitor for free, a rather ordinary Phillips 107e5. Not ideal for resolutions more than 1024x768, but fine for lower resolutions, which I am interested in. If I start playing fps at 1600x1200, those 20 year old monitors will wear out fast and waste a lot of energy too. Eg playing Doom, Quake, Blood Duke Nukem source ports at low res and high refresh rates gives a unique look and motion not found on LCD monitors.
I connected the laptop, an old i7 6700 with gtx 1060, via HDMI to VGA converter. Unfortunately Windows 10 is not that low resolution friendly, unless you buy special adapters or put an old AMD card as secondary GPU to allow custom low res.
Hence I settled for Linux Mint where it is easier to set custom resolutions and high refresh rates by just editing the xorg file.
On retroarch I used the CRT Switchres settings at 120 hz and vsync interval at 2. This was the only way to allow low resolutions like 24op on non 15khz monitors. Majority of video games became ultra smooth this way with the unique motion of CRT. Also the low res produced native scanlines looks that make the games look even better than using shaders.
However there was an issue with DOS games. Because I was using DOSBOX instead of running DOS natively, they struggle to maintain a stable frame rate as DOSBOX still lacks in that department.
Fortunately on my desktop, an old i7 4790K with a still decent GTX 1080 GPU, I connected a G-Sync monitor, an old ASUS ROG PG348Q that supports up to 100 hz and ultrawide resolutions up to 3440x1440. This is the max frames the GPU can handle, so any higher refresh rates would be redundant. I set Nvidia control panel at 97 fps max frame rate, enabled Gsync for full screen, latency at ultra and forced vsync on for all games. This means that I have to disable vsync for every game. Games look and play spectacular on that monitor, though for ultrawide I have to use fan patches or hex edits for a lot of games as they do not support it natively.
When it comes to emulation, on Retroarch I just used the VRR Freesync/Gsync option, leaving Vsync to on. Games are as smooth as on the CRT display on Linux. Only downside is that I have to rely on shaders for a better quality picture.
However the thing where Gsync gave the best result, even surpassing CRT monitors and TV sets, is in old MS-DOS games. I am using DOSBOX-X fork with Opengl renderer and vsync off. Not only is the motion smoother for majority of games, but in some cases it is even surpassing the results on native DOS, eg in the case of the Lion King. With vsync to host, it became almost as smooth as the console version. However other games freeze or become very slow with that option.
Also tested it on MAME. Though they recommend to have Vsync on, I turned it off as well as triple buffering. Gsync tests showed the correct results in MK1 coin portrait rolls and Samurai Showdown 2 shadow flicker. Now finally all those games with weird fps counters play smoothly without lag and breakups.
This is even better experience than the best arcade ports.
WinUAE also supports gsync and results are evident there too. Unfortunately monitor refresh of 100hz is not sufficient for beam racing, but it works on the CRT monitor if I set 320x240x157hz.
This is the ideal emulation setup if you are not interested in scalers and converters or old CRT televisions.