I've been using Graphene for several years and I love it. I could never go back now, Google android feels so incredibly bloated and invasive by comparison.

Double check your backups just to be safe, and then go for it. It's not hard to revert if you hate it. There is a big of a learning curve, mainly just using the alternative app stores like Accresent, F-Droid, etc.

But once you spend a bit of time getting your apps installed and your system set up the way you like, you'll love it.