From ACR 3.7 README:
Important Notes Regarding Camera Raw 3.7
There are several significant changes to Camera Raw 3.7 in how it handles auto and default settings:
• Applying auto settings by default is no longer controlled on a model by model basis, but instead there is a single global preference checkbox “Apply auto tone adjustments” that controls this adjustment for all camera models at once.
• Camera Raw 3.7 no longer supports per slider auto adjustments. One “Auto” control at the top of the panel now sets the Exposure, Shadows, Brightness, and Contrast sliders to their auto values. The “Default” control at the top of the panel sets these same four sliders to their default values.
The keyboard shortcut for the Auto control is CMD/CTRL-U. The keyboard shortcut for the Default control is CMD/CTRL-R.
• Double clicking on a slider to set that single slider to its default value.
• Shift double clicking on a slider to set that single slider to its auto value.
• Previously, default image settings could only be applied per camera model. Camera Raw 3.7 can now:
o Apply default image settings specific to a camera serial number
o Apply default image settings specific to a camera ISO setting
The additional criteria are located in the Camera Raw preferences.
• The default settings (including the global auto preference) are now shared with the DNG Converter.
• The DNG Converter requires 10.3.9 as a minimum operating system.