reliable and flexible yes,
powerful , I disagree.
mysql is missing alot of features that keep it from being a choice of enterprise commerce. Stored procedures are still a big miss...
Its great for simple applications, but you probably wouldnt use it in a 3 tier or better environment.
It is very fast, and well suited for some roles, but it's not full featured enough to go against Oracle/MSSQLSybase/Informix yet.
But, you get what you pay for
