Personally I prefer the new one. Previously you had what, eight submenus for notifications? Now you can see them all at once, the unread ones are clearly marked, and once you've been in the notifications menu they automatically mark themselves as read without you having to do it manually (which was previously required). If you need to go back and refer to an old one it's always available in the menu too.
I guess it might suck if you only turn on your PS4 once a month, and come back to 100 unread notifications, but I strongly suspect that those sorts of people only rarely receive any notifications anyway.