I love having the capability to monitor all of these items, and really support the work @radhoo is doing.
From that support, some feedback from the two devices I have.

Good news is that the European and American airport security and the airplane staff did not even blink when I brought one with me. Although the airport security may have been distracted by the drone I brought too 😉

Build quality really isn’t what I’d expect from such a relatively pricy device: the screws were rusting at delivery, at least one of the devices had the beginnings of rust on the tube and the shielding internally, both lost the cap on the GPS antenna (double sided tape seems to have solved that), both have creaking touch screen enclosures that don’t quite align the screen, one of the switch plastic was just damaged.

The device works well for me, but there are some details I’d like improved:

• Having a mode that does not sound the geiger events, but does sound alarms at high values: for everyday running I don’t want to here the normal background radiation, I do want to know when something is going wrong.
• Responsiveness of the user interface is low. It seems to be a combination of the CPU being too busy with other tasks (disabling modules helps), very specific timing of what constitutes a tap, and sometimes it would not detect the release of the tap. Due to how the enclosure of the touch screen is done, it is not always easy to use the extreme values of the SSID/key entry. I ended up using a iPad Pro stylus for most of ths.
• I would love to have an (ordered?) list of SSID+keys to connect to. I have signed it up for my phone, but iPhones won’t connect to a WLAN and provide an access point. So I’d love to have the capability to list both my home, work, and mobile WLANs and the device connecting to whichever is available.
• I would like a night mode that disables all the LEDs (GPS, ‘data’ and charging), so I can have the device in my (hotel) room.
• It would be nice if the bottom is entirely flat, so that the device can be stood upright. I now use a gorilla pod with a clamp for this.
• I can’t get offline results to really show well.
• The device starts to beep constantly sometimes when connected to USB power sources (including the airplane charge port). I’m not sure what that means?
• I would like that holding the power on button for a while, turns the device off. Preferably hardware based in case the software misbehaves. Not everyone has a needle with them to push the reset button 😉
• I would like the location information of the sensor to be somewhat obfuscated ideally.