MariaDB vs Percona server - main differences?
Percona Server with XtraDB is the closest to the official MySQL Enterprise releases from Oracle. It is more conservative than MariaDB, which includes extra storage engines and more far-reaching code changes. (MariaDB is also built on the Percona XtraDB storage engine, but adds more changes to the rest of the MySQL server.)
You should check out comparison results at http://vbtechsupport.com/606/ and http://vbtechsupport.com/657/