No I'm not. I use OP and LineageOS, which is nice also.
I had Graphene back in the day with my Nexus9 but it was quite laggy then. Lately I have heard a lot of good experiences with Graphene and latest Pixels and considering Pixel as my next phone.
Discussion
Yes GrapheneOS is good check out the features page and have a good read of the Usage and FAQ pages at grapheneos.org then if you have further questions requiring a hands on, daily driver experience from a user then hit me up.
Look forward to hearing from you both.
PS Dont forget that Lineage OS uses Google Services by default at the system level. It is not a 'degoogled' OS (common parlance misnomer but I know what you mean) regardless of GApps or MicroG being present.