Now I'm armed with two sticks - one with the official Arch distro, and one with manjaro, in case I don't manage to get regular arch working.
I'll probably stick to the first distro I can get running with i3, working wireless and gcc, so arch probably has a good chance to be my final choice (if I like pacman)
You might also try "Arch-Anywhere". It's got a very nice install script, and is minimal. You'll end up with a very basic installation of Arch, probably similar to the one you'd get with a more manual installation. This is how I got started using Arch, and I've learned more about Linux than I ever would have been able to with Ubuntu or Debian.
> Arch has turned out, surprisingly to be much easier to maintain, since things are well documented and consistent.
Agreed. I've moved all my private servers [1] to Arch, despite everyone warning that it will break all the time, and I've never experienced any sort of breakage (except when I did stupid things myself).
[1] Currently, there are three: one physical machine as a homeserver, and two VPS for public services.
If your first installs are going to be gcc and i3, then I think you should give the standard Arch install a shot. It takes a basic understanding of what's happening during the install process, and I'm guessing if you're kicking off with i3 then you're comfortable with things like partitioning and configuring a window manager. If that's the case, installing Arch will teach you things that an Ubuntu install definitely won't, and you get a fresh clean minimal install too.
It was a big help to get more into i3. It also includes a lot of helper scripts. I used them in the beginning to get things done and later switched over to the "real" commands. inst -> pacman is an example for that.