Got a Framework 12 and have all sorts of tiny annoying but somewhat manageable problems with it.
It used to overheat and then throttle to 400 Mhz every few seconds on high load. Overheating meaning 100°C. After a long time being annoyed and thinking "did I do something wrong" I reached out to support, and eventually got a new motherboard. It's better since then, but it still gets hot quickly. Also, if I just idle, like maybe a few Browser tabs and that's it, it will get somewhat warm ~65°C and I just don't get it.
For some reason, it sometimes does not find my hard drive on boot. Works the second or third attempt, and is no software problem.
The light detection thing has to be disabled in software to be able to use the brightness buttons.
At the start, my wifi sucked really bad, just on this device.
Having some more ports than just the audio jack and the extension cards would be neat too.
Also, it was really expensive.
So yeah, I sadly wouldn't buy it again, I think. The concept is really neat, but I've had too many annoying little problems. I still do use it as my main computer, and it works reasonably well, is light and well transportable, works with my docking station easily, etc, but those issues are annoying.