Would you recommend it? I'm typically a huge fan of hack'n'slash games.
I would hold off for a sale. Unless you enjoy doing the same thing over and over again, but I think you've had your fill from Destiny already. I would wait and get AC: Unity instead if you're looking for that sort of game. Mordor isn't hack and slash in the sense of DMC or Bayonetta.
I'm really surprised that the messaging system is still so rough on the PS4. I get a notification that I got a new message, but when I go to my messages nothing is there and the refresh icon just keeps spinning it's wheels. When the message finally came in the damn thing doesn't recognize that I've read it so despite idling in the message window for several minutes I still have a (1) notification.
So you should get an XB1 just to send messages relatively hassle free. XMB is still, quite frankly, a mess.
@zevvion: I'm surprised more Titans don't use the bubble shield in control matches. One titan can throw down a shield and then another sits and waits with his super for people to come inside the bubble.