I love graphene, but I'm biased. @final might know more about both systems than anyone. I hope he chimes in. I think he might have compared the two on SN in the past.

GrapheneOS is the way to go imo. Calyx is a good alternative if you don't have a Pixel (especially when compared to other privacy OS or so called "privacy phones" - avoid those), but a few searches comparing the two should yield the reasoning.

Some GrapheneOS staff are a bit intense in defending the OS against myths and when measured up against CalyxOS. Might turn off some people, but putting that aside, they aren't necessarily wrong.

Also you didn't mention LineageOS, that I find it quite good for a non-pixel phone.

I always ask Reddit everything

i opt for calyx because if you are familiar with a technology there is no need for new one

We haven't received many posts on Calyx, and tons on Graphene, so I've assumed the move is to use Graphene.

Graphene. But they're in trouble (and technically so is Calyx). Calyx is not a replacement for Graphene: it's like saying i replace my safe with a stitched pocket.

Graphene is security first, and they have really high standards. But they're a security oriented distro, so you have to have user discipline to make the privacy part work. Calyx is more of a privacy but not so much security build, so you don't get actual security in favor of de-googling.

Ultimately it's what you value most. If you feel like you need real-life security, then GrapheneOS is the way to go. If you just want goog to not know you, but dont care about borders, governments and police, then calyx may do your job for you as long as you realize you are vulnerable when taking a flight or when the govt turns against you.

Is that a Pixel 4?

I'm also running Calyx but I think I'll switch to Graphene sometime next year. It seems to be better recommended than Calyx and I'm interested to see what differences they have.

My vote goes for Calyx. The web installer makes this way, way easier to deal with.