Really good

I never used paid version as the free version is enougth for my every days need. I mostly use this to switch database from production to localhost or to make some backup.

Here are some cool things about db migrate
– Keep wordpress serialized field
– Search and replace always worked to me.
– Work on multisite
– don’t need to connect to phpmyadmin to do backup

You can’t really break you website if you know what you are doing. But you should anyway always make some backup before manipulating database live and try if they work / import well.