Originally they endorsed +P+ use. Later, after experiencing a few issues it was decided +P only would be a safer stand. If you pay attention to the current barrel design I would venture to say they will be endorsing +P+ again.
Bottom line: Glock has changed their approach on this subject several times over the years so I recommend you get the word direct from them.
Last edited by JR; 03-02-2010 at 16:41..