this isn't exactly what you're looking for (it compares ms sql express to the others and uses an older version of mysql) but it's a start. I've used mysql and ms sql a bit and although ms sql is easier to manage due to it's GUI, I find mysql a better option for me most of the time. I don't mind getting down and gritty at the command line. I mostly develop web apps though with PHP, so mysql is the obvious choice. I have used it in a few VB.NET projects though and it worked very well.