Almost every single file in WinSxS is a hardlink. File that are not hardlinked in WinSxS are in hibernation, not currently in used. But moving WinSxS will not reclaim any thing. A file is only removed if all the hardlinks are removed. Link Shell Extension
will give a visual indicator of all hardlinks in a directroy. As well as a tab in the properties for hardlinks.
On my system there is about 3 GBs worth of hardlinks in the WinSxS folder, it is also under 5 GB in total size.