What is the opinion of the GOG community about RTSS as an FPS limiter? Is it worth it?

Personally, I like it.

What do you think?

sucks if you don't use a Nvidea card, but who cares about those pesants

LOL, why?

Not following what you mean or are suggesting.

Tried it a few times in the past, and I think it's alright. But I've stopped using it since I can just use NVIDIA control panel to do the same thing. And if I recall correctly, you need to have the program turned on every time you want to have the FPS limiter to work when we're talking about RTSS.

I use the scanline sync function, which I have set to -1 default but certain games require more work.
I began using it because the normal framelimiter can be very rough in some games.

A bit of a technical article on how to use scanline sync, which after a day of trying I got it working properly and the results are very good, like you are having freesync or g-sync while your display does not support those.

https://www.resetera.com/threads/guide-how-to-use-rtsss-scanline-sync-to-reduce-stuttering-screen-tearing-and-input-lag-on-pc-alternative-to-vsync-g-sync-and-freesync.138764/

For a bit of context, I'm using an RX 580 on a 60Hz TV.