Bravo is not world class, but very good.
Ter Stegen is not ready yet, but in 1-2 years he could be world class
Mathieu is a good sub, but mediocre at best against top opposition
Rakitic is nowhere near what is required for a midfielder at Barcelona, also a very good sub and squad player, but not a great starter
Douglas is dougshit, not his fault he's here
Vermaelen has gone missing
Suarez is world class, but he needs to show it in a game by game basis. I'm not seeing it so far. He needs goals.
The only really good signing is Bravo.