At the moment Courtois is one my favorite players, but I still believe Mourinho did a huge mistake when he choose him over Cech as the nยบ1 GK. Courtois is no better than Cech. Cech is a Chelsea legend, and was still 32 years old. I mean he still had at least more 5 years at top level. GK keepm playing untill late 30s. Buffon is still a quality GK, van De Sar was playing UCL Final with 41. Schmeichel was winning UCL with united with 36 years.
Courtois can produce some impossible saves, but he is a liability at crosses and set pieces, and its clear he is that kind of player that put some subpar performance when he is under pressure.