There are not many goalkeepers out there who have produced better performances consistently over a season than Sczcesny's last season for us. His deficiencies are not down to lack of quality but a lack of focus and possibly seriousness on his part. Last season he cut out the bullshit and was probably the best keeper in the league after Cech and you can't have a season as good as that unless you are quality. He will be our No. 1 keeper for years to come and I'm completely fine with it. Having a decent replacement to keep him on his toes and dropping him if/when he shows signs of complacency and unprofessional behavior is the way to go and Ospina fits the bill perfectly.
Oh and those set of stats are what I imagine Brentan saw before signing a clown like Mignolet for quite a lot of money.