The best Linux distribution if you want true customisation aside from LFS.
With Gentoo now adding binary packages for even further customisation for people who prefer to use binary for things like the Linux kernel unless you actually want to compile all of that from source, as well as programs like browsers which will probably take a near eternity to compile from source. Gentoo is definitely a good rolling release distro, and it will be a bigger rolling release because you can actually compile from source, some might say you can do this on any Linux distro yes, but Gentoo is built on this concept and now that it integrates binary packages as well so you do not have to compile large software from source it is significantly better and it was a swift migration for me who used Arch Linux for a long time.
My test subject for this Gentoo installation was a very expensive, kind of old, and used, ASUS Vivobook laptop. The internet required some manual configuration but other than that, everything worked as expected.