For the most part, MariaDB is a binary drop in replacement for MySQL where you should be able to just fire up MariaDB from standard MySQL database already in production. You'll want to reference their site for any changes to be aware of (as there's even configuration settings and syntax differences between versions), but in general if you're running somewhat of a modern version of MySQL (5.1+), MariaDB 10.x (based on MySQL 5.6+), you shouldn't experience any problems after mysql upgrading the system tables.
In comparison to standard MySQL, there's a number of improvements (Percona also has many of the same and is very good too), including but not limited to:
- several other storage engines can be used
- significant speed improvements such as subqueries and joins with the optimizer
- faster and safer replication
- parallel replication
- innodb specific tunings (mostly related for speed)
- indexes for the memory(heap) engine considerably faster
- thread pools as of mariadb 5.1, even better in 5.5+
- gtid and multi-source replication
- fulltext searching support with InnoDB!
- table elimination
- microseconds implementation
- much better user stats and progress reporting when altering tables, loading data from infile, etc.
- truly open source!
I can't say there isn't anything that I really dislike about MariaDB. In the newer versions, InnoDB supports fulltext searching (implemented as of MySQL 5.6) which makes converting table engines lucrative to avoid table locks for the most part that couldn't be done before since FULLTEXT was strictly MyISAM. They can still happen in certain cases, although will generally release pretty fast depending on the queries, system resources and the amount of load the system is under.
The amount of improvements / features MariaDB has only enhances standard MySQL to be better and is practically a drop-in replacement over standard MySQL.
I would highly recommend giving it a try if you're looking for performance increases and enhancements/features that are available.
Improved speed with queries, replication, the ability to convert MyISAM tables to InnoDB now that it supports FULLTEXT searching and eliminates table locks that MyISAM would impose based on how the storage engine works (table based locking with MyISAM vs row based locking with InnoDB).
The progress reporting via the MySQL CLI is rather useful for knowing the percentage amount done from an executed command, along with indicating how long it will take (per stage).