I'm currently running Eclipse Kepler, with the Android Plugin.
I recently created a new Android Project, added a few activities and everything seemed fine until I started noticing that Eclipse, everytime I opened an existing .xml file (strings, values, mainactivity, you name it) the progress console showed that Eclipse is loading the "data for Android 4.3". I mean, literally, everytime I open a .xml document.
It's quite frustrating because it loads the same package over and over again and it can take some considerable time.
The SDK is fully updated, so is Eclipse.