Verdict: FreeBSD
You read documentation voluntarily and you want a system that behaves the same way twice. FreeBSD is a complete operating system: kernel, userland, ports, and docs all from one project that acts like they actually tested it together.
What you get
Section titled “What you get”- ZFS as a first-class citizen. Snapshots, boot environments, send/receive, compression. Once you have it, you will refuse to live without it. Period.
- Jails: containers from before containers were a personality. Lightweight, powerful, and built in. Not a third-party hack. FreeBSD got it right before Docker was even an idea.
- The Handbook. If you have a question, read the Handbook. It answers questions Linux wikis answer with “might be outdated, check the forum.”
- Ports and pkg: package management that doesn’t change every six months. What works today works next year.
- Infrastructure pedigree: Netflix, Apple, Cloudflare, Sony, Reddit all run on it. If it’s good enough for that load, it’s good enough for your server.
- Stable, predictable releases. A new major version every 2 years. When you upgrade, things stay the same.
What will hurt
Section titled “What will hurt”- Wifi. Improving fast, but check your chip first. It might not work. Ethernet is always honest.
- Laptop suspend/resume is a dice roll on exotic hardware. Desktop? Fine. Laptop with modern chips? Maybe.
- Some hardware support arrives years late or never. New GPU? Maybe not. Bleeding edge USB device? Good luck. This is, incidentally, why ChaosBSD exists.
- Fewer packages than Linux. Most things exist in Ports, but some newer stuff doesn’t. If you need the absolute latest version of something, FreeBSD might not have it yet.
Getting help
Section titled “Getting help”- FreeBSD Forums - active, knowledgeable community.
- FreeBSD Mailing Lists - questions-@ for general questions.
- FreeBSD IRC on Libera.Chat.
- Man pages. Type
man 1 intro. Thenman sysctl. Thenman rc. Then start reading. It all makes sense.
First steps
Section titled “First steps”- Use UEFI, not BIOS boot, if your hardware supports it. FreeBSD’s BIOS boot is older.
- Don’t use UFS. The installer offers it but ZFS is better and you’ll regret it later.
- For servers, use the latest stable release. For tinkering, the current development branch is fine.
- Read the Handbook section for your hardware. Yes, really. Not later. Now.
- Ethernet setup is two lines. Wifi setup is “does your card work?” first.
Where to start
Section titled “Where to start”Download from freebsd.org, write to USB, install with ZFS, and follow the Handbook step by step. It is written in that order on purpose, not by accident.