I’d say Gentoo is kinda… grittier? It’s less eager to help you out and be nice. Where Arch is like “Oh, you want Foo? Okay, here’s Foo, along with Bar and Baz to go with it” Gentoo is like “'Kay, building Foo.” Then you wonder why Foo doesn’t do Baz-y things and how it’s any good to anycritter without Bar, and it turns out those are compile-time options and you didn’t set the USE flags to include them for Foo so it wasn’t built with them. Your system never downloaded, built, or installed them at all because you didn’t tell it to. It pretty well expects you to know what you want and what you need to do it >:3 … that, and have a nice beefy CPU 😅 I tend to alternate between Arch and Gentoo every few years. Am currently using Arch (bytheway ;P) after switching from Gentoo for some comfy convenience but I kinda love both.
Funtoo is… I don’t entirely remember what it was meant to be, compared to Gentoo 😅 I vaguely recall it was supposed to have some nice features but wanted me to do sensible things like stop using ancient GRUB so I just didn’t get into it. May try that next.
As for BSDs, I’ve kinda wanted to run a BSD for a long time but none of them are what I actually want (despite my nonsensical eagerness to be and do weird wherever possible- er, I mean, despite how good and stable and cool they are!) so I just kinda poke one or two every few years, accomplish nothing, then give up. I do want to like them, though 😅