Well, I was forgotten in the queue it seems. I complained and received my LibreM 5 within a week.
First impression
The package is clean and neat and heightens the expectation while opening it.
The device is heavy, you can hurt someone if you throw the phone at them. Metal all around, which is needed because the device runs lukewarm. (Just 6 hours of operating time). Louis Rossmann would approve of the space for your nail in the corner, which helps open it up (there's no need to open it, but it has the bottom half for a fat battery and the top has all the electronics, which means the battery is not the primary heatsink, as with conventional phones). The clicks it makes when closing are satisfying ASMR.
Usage
You are greeted with many passwords: First only at (re)boot for the LUKS encryption, then for your user each time you unlock the phone. I've not yet found a graphical way to change the LUKS password, so I need to read up on that first (adding a secondary LUKS pwd, test that, then remove the primary one, and hope it keeps booting). The user password is easy to change.
The ecosystem is Gnome. And as a KDE fanboy I struggled finding the right tools that would not import half of KDE into the device.
The autorotate works fine enough. And VLC is capable of not losing frames when playing a 1920x1080 at 24 frames per second, with AAC 44.1 32 bit samplerate. (A highres Music video with lots of movement). Display is excellent. At maximum brightness the white is white (while my other phones are off-white) and the maximum intensity is the same or better.
The keyboard is not that of android, so longholding keys to get alternative characters is not there. There is a console mode, where you get access to F keys, but you lose shift, so you can't do a shift-F1 (afaik), but Control+Alt+F12 is accesible. There is also a limited set of emoji's (I'm pretty sure you can get down to the terminal to create your own groups, but I havent touched that yet)
The OS still needs polishing. It boots at 200% zoom, which makes it all readable, but some applications do not like being squeezed into such a tiny space. Rotating helps, but not always.
It being Linux means you can play something in VLC, and browse while playing it, as it is not really in the background. Android would stop all applications that don't have focus.
I also set up passwordless ssh using an SSH key, so I could send some images and test them. The image viewer (Gnome Image Viewer) crashes every now and then when it detects webp/webm in the directory, even if it ignores the files for displaying. I might have to apt-get install something else.
And Gnome contacts can only import one contact at a time (so the trick was to concat all the files into one VCF file).
Send and receive through bluetooth worked (from/to another phone), you just need to pair them.
The three kill switches are nice (one for GSM, one for Wifi/Bluetooth, one for microphone/audio) Note that every time you enable back the GSM, you have to type in the PIN.
Desktop Mode
Just like the Google Pixel, you can connect the phone to a monitor/mouse/keyboard and enjoy highres. It felt even more useful, as you have all applications you can install using the Debian-ARM repository (similar to Pyra/Pandora). But YMMV, as you don't have native Google software. CPU is ok to work with. But there is no graphics acceleration. So slither.io on the browser crawled to unplayability. But normal webpages scrolled well. Having access to a real Firefox browser (instead of a skin) is quite the luxury. Mouse movement never got stuck, and moving applications from the first screen (phone) to the bigger screen (desktop) is possible after you learn how.
Audio
Audacity shows too much hiss when recording from the build-in mic. However, playback is top-notch. Connecting Bluetooth headphones with microphone is easy and eliminates the hiss (because it's converted to digital before it's being send to the phone). Bluetooth headphone autonomy (how far you can walk from the phone) is identical to my Android phone. Because the CPU is always in high-power mode, there is no interruptions in the audio, like you get when the Android phone is in low power and it decides to to a background task.
Backlight
The backlight is yellow, not the ugly blue you get on most phones now. And you can modify the intensity of it, which my Android does not have (it's just on/off, thre is no dimming)
Camera
Ugh, a weak point on the phone is the camera. And it's due to the software (It is unfinished, and it warns us about it, so its a known issue). The camera produces 13.3MB DNG files, which are then converted to a 400KB to 1.4MB JPG files, which is what you get to see. Autofocus is not controllable in the GUI yet, and the guessing by the camera application is sub-par. As you understand, this Fairly low resolution and I have some dead pixels in the sensor to boot. It's... functional, but don't expect good pics. (See the IMG*.jpg ; you can crank contrast up, and see for yourself that the darkness contains much more information than needed - maybe a good thing in the DNG, not in the jpg)
Conclusions:
+ Powerfull Linux programs (requires Linux knowledge to make use off)
+ Good Audio
- Too low resolution to display most windowed programs (can be mitigated by zooming back to 100%)
- Low battery life (like... dude, this is the total opposite of a Nokia)