Hi @Mithrandir
I've had a flir usb dongle before, early edition with microusb, 160*120 thermal image although It feels lower.
FLIR ONE -
https://amzn.eu/d/3uC16PPI had issues with connectivity on it, had to replace the internal battery and buy an extra OTG connector to get it working. It did feel a bit of bother when coming to use it. So think I prefer a full unit, but that was just my experience.
I did almost go down the infinity ray route, as the P2 has the macro lens option. I've not seen one for any topdon products. I ignored seek due to the 9hz limitation. I also steered away from AliExpress/Bangkok etc incase was warranty issues.
Ultimately I just went on price as no one highlighted any specific pro/con towards a brand or form factor.
Topdon tc003 RRP was £499, but on eBay was £429, however they offered 20% off code, and topcashback added 20% too which has tracked, plus there was another £20 off. In the end it cost £267 which I felt was a reasonable price.
The tc001 which is equivalent to infiniray p2 pro was as low as £150 on eBay, and the hikmicro B10 was £180 on Amazon. This work out cheaper than the P2 pro.
I suppose one drawback of the tablet/handheld form factor is the same as the flir. If the battery totally does you need to dismantle the unit to replace it. A positive though is its much easier to lend to someone as it's all in one, pickup and go.