i agree, the half speed fan was a very nice option. i "upgraded" to 2.3 build 797 a few days ago and sadly the half speed feature is missing (or hidden where i can't find it!). in the middle of winter when the ambient temperature is 0C and the 2600MC Pro is set to -10C or -15C and the cooler working at 25% with the fan at half speed there isn't much reason to deal with the added vibration of the full speed mode. ZWO, does running the fan at half speed damage the camera??? (if not, please give this very nice feature back).....thanks