Although I’ve recommended it, there is one issue that’s irritating. Just today I tested the VollaOS install and all systems go. Then I tested Ubuntu Touch, same. SFOS something is wrong with the video recording (camera otherwise makes nice photos). And the networking is a bit odd. Some, @Fellfrosch , can’t get stable hotspot working altough that works for me. So, there are some odd bits.
The Gigaset GS5 with 2GB less RAM does not have the video recording issue.