I just wanted to share my experiences with the Fanless Mini PC Celeron J1900 Quad-Core . I ordered it from a Chinese retailer for about $150 with 4 GB RAM and 16 GB SSD.
So after a few installs I finally laid out the correct Network Setup ( I am no professional) and it runs extremely smooth with the basic configuration plus a dns_blocker.sh to filter advertisements by DNS-address. After a week I also activated the Intrusion Prevention System and I am extremely happy how it all works. My Nextcloud behind the firewall works perfectly fine with NAT and DynDNS on IPFire.
Only drawback is that the device has no HDMI connection so I had to get a VGA-cable to properly install IPFire first.
I saw a lack of success stories in the hardware section so I thought I share mine.