MySQL is better than YourSQL ;^)
To address some of the performance issues we have been seeing on the site (especially when trying to display the details of a trial) we have switched over to using MySQL instead of MS SQL Server. On the trial details page, this brought the time spent querying the database down from around 26 seconds to about 0.2 of a second, and that’s my kind of speed up!
My best guess is that it is not MS SQL Server that is actually causing the bottleneck, but rather the database connection software that sits between it and Django. The lesson I think we have learned from this is that when using Open Source frameworks like Django and Rails, it is best to stick with the databases that they support directly (usually, MySQL, Postgres, and Oracle) since there is a better chance that the database connection software will be more actively maintained.