The PS4 has got a well known problem that afflicts many gamers around the world and that problem is, you guessed it, horribly slow messaging capabilities. Many users who use the entirely text based tools for communication with their gaming friends and co-workers have found the service nigh-unusable, despite a recent firmware update that was expected to bring a fix.
Though you can rest assured that the issue is a known one and that the problem is indeed being targeted for fixing. This was confirmed, albeit rather quietly,when good old Shuhei Yoshida responded to user questions about the service. One fan in particular told him it was still slow to send and receive messages post update, to which he replied “we are aware of the issues and our team is working on them”.
And in a separate act of professionalism and common decency he apologized for any inconveniences that the user experienced whilst using the service. Props to Shuhei.
[Source]