OS: Mac OS X (El captain)
nw.js version: 0.13.4-sdk
App.dataPath is returning ~/Library/Application Support/<name>/Default while the docs say it should return ~/Library/Application Support/<name>
The name of the package from package.json is devlog.

There is a directory named Default in that location and has files related to preferences, cookies etc.
Confirming this on Windows 10 x64 nw.js 0.13.2-sdk. nw.App.dataPath returns %LOCALAPPDATA%/<name>/User Data/Default. Should be %LOCALAPPDATA%/<name>.
Same thing here on Ubuntu 15.04 x64 with nw.js 0.13.4-sdk.
Same behaviour in [email protected]
same behavior in nw0.14.2-sdk. I have noticed one more thing on Mac. In nw0.12.3 folders like 'Local Storage', 'GPU Cache' were created in 'library/Application Support/[app name]/' but, from nw0.13 onwards they are getting created in 'library/Application Support/[app name]/Default/'.
So this may be the reason of why App.dataPath is returning the new path. It's just an observation. I haven't thoroughly looked into it.
0.14.4-sdk LTS - still an issue on Windows 10 x64.
why is this changed indeed? We have User Data/Default at the end, like:
on Windows 10
C:\Users[username]\AppData\Local[app name]\User Data\Default
while it use to be:
C:\Users[username]\AppData\Local[app name]\
Now we have to run some manual migration ...
As chromium does, stores all the application data in the default profile folder.
App.dataPath returns a path with a directory named Default at the end on nwjs 0.21.6.