I don't like the dsl. While admittedly it is entirely a question of preference, I find it more natural to write some ruby code and then assert(something). As an example, from Hartl's tutorial we have a test dealing with microposts:

    subject { @micropost }
    it { should respond_to(:content) }

I prefer writing:

    assert @micropost.respond_to?(:content)

I haven't looked at rspec in a while and in the rspec example I don't remember how long the subject stays in scope nor would I remember to put braces between 'it' and 'should'. In the testunit example, it's all ruby, there isn't anything more I need to know.

It sounds strange, but even though the rspec example reads more like english, I find the assert more readable. Maybe it has something to do with the braces.

As a beginner, there are so many choices you have to make and so many things you have to learn. Rspec adds another item to that list. I would have preferred to learn to write tests with testunit and fixtures and then be presented with rspec, cucumber, factories, etc., a little later.

Have you used both rspec and testunit or just the former?