Timely post by Steve Stafford over at Revit OpEd on
Double-Clicking Tags! Here
are some additional tidbits:
Revit 2014 expanded on some of the double-click functionality
introduced in Revit 2013. By default you
can customize these settings under Options > User Interface >
Double-click Options:

Another change was made to editing parameters in tags. In Revit 2013 to edit a parameter in a tag
you had to select the tag then single-click over the parameter. If you double-clicked on the tag or parameter
it would open the tag family for edit:

Based on user feedback in Revit 2014 this functionality was modified. You can still select the tag and single-click
to edit the parameter value. But now you
can also double-click on the parameter value to edit it. If your mouse cursor is near a tag parameter
double-click to edit tag parameters take priority over double-click to edit the
family. Even if you have
double-click settings for Family set to ‘Do Nothing’ double-click to edit parameters
still functions:

These double-click settings can be set in the Revit.ini
using the following lines; look for [UserInterface]:
[UserInterface]
DoubleClickFamily=EditType \ EditFamily \ NoAction
DoubleClickSketchedElement=EnterEditMode \ EditType \ NoAction
DoubleClickViewOnSheet=ActivateView \ NoAction
DoubleClickAssembly=EnterEditMode \ EditType \ NoAction
DoubleClickGroup=EnterEditMode \ EditType \ NoAction
DoubleClickComponentStairs=EnterEditMode \ NoAction
(All available options per category are included after = include only 1 setting)
Speaking of the Revit.ini, you can also preset the new 2014 selection
enhancements there as well; adjust or add the following lines to the Revit.ini. Look for [Selection]
[Selection]
AllowFaceSelection=1
AllowUnderlaySelection=1
AllowLinkSelection=1
AllowPinnedSelection=1
AllowPressAndDrag=1
0 = Disabled
1 = Enabled