Time of connection has been considerably reduced using Calibre 2.3, compared to 2.2.
I'm the user you talk about
But, unhappily, 2.4 release has broken all your changes. Time of connexion is twice worst than in 2.2 : 26 minutes for initial connection, and the same after transfert of 38 books.
You told me that it would be fixed in 2.5.
BTW thank you for your quick answer.
Edit : When writing this message, I hadn't read the pinned message. Thanks for all