I have had mine running for a while, very happy with it. I have the armour cooler and was very happy during most use it rarely goes over 60 degrees.
The other day I had it doing a lot of work so it was using the CPU at ~100% for well over an hour before I left. In this whole time, I did not get to 90 degrees (but got to very high 80s).
I was surprised because I kept seeing claims that it overheats easily, so I went to check the chip's frequency, thinking 'I have never seen mine throttle' and apparently the chip should reach 2.7GHz, but I have never seen btop report over 2GHz, so it looks like mine has been throttling all the time, which explains the generally low temperatures.
I am running armbian. Has anyone seen reported fequency higher than 2GHz in real usage?
Edit: Turns out it reaches the expected frequency per core and with the armor cooler does not get to throttle. My confusion was caused by not understanding how btop reports frequency. Thanks to everyone who helped!