I can kind of see why people are disappointed, I think when it comes to successful transfers it's easier to just compare them to the recent previous buys.
So who has come in, in the last 4 years that is better, the same, or even potentially the same as:
Silva, Yaya, Aguero, Nasri, Barry, Tevez, Kolarov, Lescott, Johnson, Dejong, Clichy, Dzeko, Savic.
In my mind only Fernandinho, DeBruyne, Negredo, Sagna have a good argument.
So far Sterling, Ota, have a chance.
Mangala, Bony, Fernando (albeit improving), Navas, Rodwell, Sinclair, Garcia, Maicon all weren't anywhere near.
all my opinion of course, but i look at the previous list and see champions, i look at the players since and see exactly where we are.