Reclaim that space!
RAD Studio uninstall is not all inclusive, it seems. After uninstalling XE6 and XE8, the shared samples and kits still linger.
14.0 3Gb in 58k files (XE6 uninstalled)
15.0 3Gb 56k files (XE7.x Installed)
16.0 2Gb 51k files (XE8.x uninstalled)
17.0 2.8gb 60k files (10 Seattle installed)
So, that’s just above 5Gb reclaimed by removing the two dead directories.