The SIM card slot still fail off. This is bad. We optimized once and it should be OK.

Yes, but it’s not a huge problem, I think…I imagine most people will simply do what I did and clip it back on.

It is using a microSD card so pls use the correct SIM size.

I don’t know what you mean by ‘microSD card’, since that is the other slot. I’m talking about the SIM slot. I have all the adaptors and none of them seemed to fit properly…note that I’m just talking about it fitting in the metal clip part, not the plastic part with the contacts (it fits the plastic part just fine). I’m of Nokia vintage, so I’m reasonably used to how these trays usually work - ie you put the sim in the clip and then fold it down into the plastic part. Perhaps this one doesn’t work the same way and you’re supposed to put the SIM into the plastic part, and the put the clip down on top of it?

Its power consumption is big so 12V make it stable. As it is not designed for travel so we didn’t use 5V.

Yes, except I have lots of high capacity USB sockets, and only few ‘mains’ sockets. If it was 5V USB, like my phone(s), I could choose which I want to use.

If you travel to China this may be a problem. Most of the time openvpn does not work because of the firewall. You may bring a roaming SIM card which by pass the firewall automatically in case your vpn does not work.

I’m not a stranger to China so I have my solutions. I do wonder what you mean by a ‘roaming SIM card’, though. How would that by-pass the firewall? Surely it will simply get me onto the Chinese side of the wall, and I’ll still face the same problems. Actually, I’ve used an unlimited data SIM in my phone (2nd SIM) and I know I still need to use VPN to make things work.