I think you have bought good players, but it will be interesting to test the strengthened view.
So Cech Vs Courtious (Is that really stronger. Both very good goal keepers and I know Cech maybe aging, but he would walk into most PL teams)
Ivanovic Vs Luis (I actually thought Ivanovic played RB, but hey what do I know. Again, interesting to see the real difference)
Ramires Vs Fabregas (Don't think there will be much debate on a player level, but is the combination with Matic any stronger, different types of players)
Costa Vs Eto (Both have excellent overseas scoring records, I will wait to see on this).
Maybe I really am blinkered, I see good players replaced by good players, I don't see weak areas being strengthened, except for maybe upfront. On paper Torres, BA, Eto was quite a front line, just didn't work at Chelsea. Will Costa?