The replication performance leap from MySQL 5.5 to MySQL 5.6 is more than 4x.

#wget http://dev.mysql.com/get/mysql-apt-config_0.3.5-1debian8_all.deb
#dpkg -i mysql-apt-config_0.3.5-1debian7_all.deb
#apt-get update
#apt-get install mysql-community-server

MySQL 5.6 replication performance
Install MySQL server 5.6 to debian