Many years ago, when I actually paid attention to such things, I rejected MySQL in favor of PostgreSQL because of the former’s terrible defaults (e.g. no ACID guarantees on the default storage engine at the time, MyISAM) and missing features (in 3.23, no subqueries, stored procedures, views, etc.). The only time I regretted it was when dealing with other software that required MySQL and would not work with PostgreSQL.
Looks like not much has changed. http://grimoire.ca/mysql/choose-something-else