I was looking in our Netonix Manager and sorted the list by temperature. A quick login to a few of the switches and the trend was that the Rev D ones tended to have a higher temperature than the Rev F ones (as much as 16 degrees C difference).
Just wondered if it was a coincidence or quirk of what locations we installed them in our field network (e.g. some cabinets are shaded, face north vs. south, etc.).
The best news, of course, is that they just keep on running even though it has been full-on Arizona summer toasty here lately.
Just for the record, they are all running 1.4.7...
