Chosing repository for production MySQL 5.5 and later

I am little confusing about which MySQL to use for production on RHEL 6.x when upgrading from MySQL 5.1 to 5.5 or later for some application for optimal functionality:
1. MySQL 5.1 is included in regular repository in RHEL 6.x.
2. What is better for production: use Software Collection and Developer Tools (RHSCL) repository (it's little more complicated to use and this is software for development, not production, right?) or switch to MySQL Community Edition repository for RHEL from Oracle?
3. Another question is about 'drop-in replacement for MySQL' which is MariaDB (now in RHEL repository too). What is difference between MariaDB and MySQL Community Edition? First is 'community developed drop-in replacement' of 'Community Edition' of MySQL.

Thanks for you help!