That's a _very_ useful addition to the application manager (it wasn't there in OS2007). Downloading packages strains the built-in flash filesystem much more than usual, because the packages are already compressed. Thus the built-in compression in the jffs2 filesystem doesn't get to do its usual efficient compression (which normally makes the built-in filesystem absorb much more data than one should think). Quite the opposite actually. So it would be much better to use that setting and get the packages downloaded to the card instead of to the limited built-in flash.