The touch sensor issue also happens on the ZMF-II clocks. There seems to be something intentionally making it not register as it happens if you try to touch the clock very slowly. However the clock KNOWS that it's being touched. At least on the ZMF-II, you can verify that by holding your finger on that sensor that you touched slowly (that did not activate), do not remove your finger at all, and then touching the second side. This will cause the first side to switch to that side (as if you pushed the first sensor), Then touch the second side again (without removing your finger from the first), and then the clock will switch sides again. (Yes, this is a bug, and someone reported this issue on this forum awhile back). It won't do that obviously, if your finger wasn't touching the first sensor.
I do not know if that happens on the pro, but that's how I found out on the II that the sensor is aware that it's being pressed.
BTW the Chronos chess clocks will always activate if you touch the sensor, every time.
Given what I know now, I will stick with the button version for any of the ZMF clocks.
Don't only one of the ZMF clocks have a button model? Pretty sure that $119 dual screen clock is sensor only, as well that "I'm blind" giant digit all metal clock.
The touch sensor issue also happens on the ZMF-II clocks. There seems to be something intentionally making it not register as it happens if you try to touch the clock very slowly. However the clock KNOWS that it's being touched. At least on the ZMF-II, you can verify that by holding your finger on that sensor that you touched slowly (that did not activate), do not remove your finger at all, and then touching the second side. This will cause the first side to switch to that side (as if you pushed the first sensor), Then touch the second side again (without removing your finger from the first), and then the clock will switch sides again. (Yes, this is a bug, and someone reported this issue on this forum awhile back). It won't do that obviously, if your finger wasn't touching the first sensor.
I do not know if that happens on the pro, but that's how I found out on the II that the sensor is aware that it's being pressed.
BTW the Chronos chess clocks will always activate if you touch the sensor, every time.
Given what I know now, I will stick with the button version for any of the ZMF clocks.