Applet KConfigGroup vs QSettings?

[David Baron]

I want to save/read configuration settings for the user (rather than global 
settings).

The applet class provides two KConfigGroup functions:
config() and config( group)

Where do these store their data? Global? User?
The group name is best the applet name()? user's name?

Alternatively, there is the qt QSettings which places stuff in  
$HOME/.config/organization/app.config or something like that for which I might 
use organization name "plasmoid" or "plasma" and my applet name.

Which is best to use for my plasmoid?

(Both have isomorphic calls and the KConfigGroup probably calls QSettings or 
its parent.)

BTW, my phoneapplet is on kde-apps.org is anyone wants to play with it.