Thunar 1.6.2 in Xubuntu 12.10 - 64 bit The file manager lags severely when accessing SFTP locations. Both GVFS or SSHFS mounted. File listing and all interface operations (drag and drop, selection, context menu) are laggy when Tree view is visible. By comparison, PCManFM is very snappy when browsing the same locations. Switching from Tree view to Shortcuts eliminates the interface lags but not the slower file listing and directory navigation.
Try a newer thunar version, maybe this has improved. But the treeview is not in a very good state. Closing.