I have a F(x)tec device. It had the issue were it no longer boots when the battery is fully depleted. It also came with Android vs Linux. It is now e-waste. To my knowledge the company died off.
I have a PinePhone. That was just a toy gadget and nothing of value as a daily driver. Another e-waste device.
I have a FuriLabs FLX1S. It is a complete pack that is mostly plug and play. The latest update improves a lot. Wayland layer works great for when you need to run an application that has no Linux equivalent, such as Kore. It still rough around the edges.
1) Chatty, SMS application, needs more features to better incorporate modern SMS communication protocols.
2) The phone dialer takes too long to start up.
3) The microSD path is hard-code so it does not play nice when being encrypted drive were /run path is used.
4) Gnome Files works better the the Index file manager but there is no proper tie-in for password management. This means you must enter your encrypted microSD password every time after a reboot.
5) Convergence station cannot handle an ultra-wide, 3440x1440, screen monitor.
6) Firefox has a buggy user experience were there is no way to hide the tabs listing or options popup from with-in the application. One must swipe out of the application into the desktop and go back to Firefox.
7) Some of the UI time out settings are too short. Such as watching a video in full screen mode. Press to show the controls and by the time you start engaging with them the controls auto-hide again.
8) Don't know of a way to export SMS history from Android and import to Linux.
Once it is a little more polished the FLXS1 will become my daily driver. It has become my Bluetooth music player. I also use it more than my actual phone daily.