The main problem restoring your old settings will cause is that the gargoyle configuration file, which indicates which sections are visible will be replaced with the old one, which may not specify all the new sections. The solution is to replace this one configuration file after doing the backup. See
this thread.
Edit:Another problem is that after reboot ntpclient may not start correctly. See
this thread for more info, and for solution.
One thing I should mention: there was another problem a lot of people were having when restoring old settings which had to do with a a conflict between the older version of the firewall script and the newer one. In the Beta5 release the restore script will automatically update the line in the firewall script that needs to be changed, so you shouldn't have to worry about that problem any more.