Sadly, it is not. Not for me at least. It is fairly close though.
Random bunch of things that are annoying or broken
I originally wanted to use stock Debian but at some point the Panfrost driver broke and the laptop could not start X. Eventually I gave up and switched to the default Manjaro. Its installer does not support an encrypted root file system. A laptop without an encrypted disk is not really usable as a laptop as you can't take it out of your house.
The biggest gripe is that everything feels sluggish. Alt-tabbing between Firefox and a terminal takes one second, as does switching between Firefox tabs. As an extreme example switching between channels in Slack takes five to ten seconds. It is unbearably slow. The wifi is not very good, it can't connect reliably to an access point in the next room (distance of about 5 meters). The wifi behaviour seems to be distro dependent so maybe there are some knobs to twiddle.
Video playback on browsers is not really nice. Youtube works in the default size, but fullscreen causes a massive frame rate drop. Fullscreen video playback in e.g. VLC is smooth.
Basic shell operations are sluggish too. I have a ZSH prompt that shows the Git status of the current directory. Entering in a directory that has a Git repo freezes the terminal for several seconds. Basically every time you need to get something from disk that is not already in cache leads to a noticeable delay.
The screen size and resolution scream for fractional scaling but Manjaro does not seem to provide it. Scale of 1 is a bit too small and 2 is way too big. The screen is matte, which is totally awesome, but unfortunately the colors are a bit muted and for some reason it seems a bit fuzzy. This may be because I have not used a sub-retina level laptop displays in years.
The trackpad's motion detector is rubbish at slow speeds. There is a firmware update that makes it better but it's still not great. According to the forums someone has already reverse engineered the trackpad and created an unofficial firmware that is better. I have not tried it. Manjaro does not provide a way to disable tap-to-click (a.k.a. the stupidest UI misfeature ever invented including the emojibar) which is maddening. This is not a hardware issue, though, as e.g. Debian's Gnome does provide this functionality. The keyboard is okayish, but sometimes detects keypresses twice, which is also annoying.
For light development work the setup is almost usable. I wrote a simple 3D model viewer app using Qt Creator and it was surprisingly smooth all round, the 3D drivers worked reliably and so on. Unfortunately invoking the compiler was again sluggish (this was C++, though, so some is expected). Even simple files that compile instantly on x86_64 took seconds to build.
Can the issues be fixed?
It's hard to say. The Panfrost driver is under heavy development, so it will probably keep getting better. That should fix at least the video playback issues. Many of the remaining issues seem to be on the CPU and disk side, though. It is unknown whether there are enough optimization gains to be had to make the experience fully smooth and, more importantly, whether there are people doing that work. It seems feasible that the next generation of hardware will be fast enough for daily usage.
Bonus content: compiling Clang
Just to see what would happen, I tried whether it would be possible to compile Clang from source (it being the heaviest fairly-easy-to-build program that I know of). It turns out that you can, here are the steps for those who want to try it themselves:
- Checkout Clang sources
- Create an 8 GB swap file and enable it
- Configure Clang, add -fuse-ld=gold to linker flags (according to Clang docs there should be a builtin option for this but in reality there isn't) and set max parallel link jobs to 1
- Start compilation with ninja -j 4 (any more and the compilation jobs cause a swap storm)
- If one of the linker jobs cause a swap storm, kill the processes and build the problematic library by hand with ninja bin/libheavy.so
- Start parallel compilation again and if it freezes, repeat as above