For the Themes-release of obsurvey, where you will be able to select different themes for your survey, we are conduction a lot of real user testing.
What we do is record normal users completing the task of creating a survey. Then we analyze all the problems they were having and come up with solutions that will solve those problems. Then we implement the solutions, and start over with recording new user tests. We've just completed our 6th round of user testing, and it seems we've ironed out all the major issues.
I think you will be able to tell that a lot of hard work has gone into the Themes-release, when it's released later this month.