MariaDB XtraDB Performance Tuning

I believe that innodb has a single read thread. However, with MariaDB you can set multiple read threads. I'm unsure what the recommended value would be. Questions - Does anyone have any experience with MariaDB and performance tuning? - Can you think of any features within MariaDB that XtraDB uses that MySQL does not? - Are there any similar settings that can I can use to fully exploit XtraDB and Maria's enhanced functionality?