Had one many years ago. Great idea but not a livable-with phone. Put me off dev phones possibly forever.
Didn't stop me getting an N900 at launch though. Great little piece of kit.
Do you actually have the Librem 5 yet?
Based on the mediocre battery life I'm hearing about on the mntre reform 2, and the need for such a heat sink there, I'm very curious what the Librem 5 situation is. They share a common SoC.
The battery life and thermals got much better in the last few months, and there's still plenty of stuff to improve on in the software stack there. With my early batch unit with smaller battery (2000mAh) I'm now able to reach 6h of idle time with modem and WiFi on without utilizing CPU suspend at all (so the phone stays reachable all that time and you can, say, ssh into it - the high figures from the PinePhone blog post rely on putting the phone into suspend). There's still plenty of work left, but I'm pretty happy with how usable Librem 5 comes to be right now.
iMX.8M can be a power and thermal hog, that's right, but once you tame it in the kernel it becomes much more approachable ;)
Mine effectively died after about three years, the USB charging port came loose and the only way I had to charge it was removing the battery and charging externally.
The freerunner was just a little too pre-market for me. I remember installing various different OS and frontend packages and trying lots of things out. It would have been fine but for one failing - whatever I installed, incoming calls would often just be silent. A phone that can't take calls is a step too far!
Freerunner sure needed some attention to make it work, but with workarounds and hw fixes for the infamous #1024 and call buzz issues it was a pretty great device. I would have used it longer if not for unbearable GPU performance that drove me towards N900 (damned glamo :))
The internet tablet line from Nokia 700 through to N900 on the other hand was by all means an “Xorg based” device, though only N900 could make calls(IIRC)