I have added an explanation why you should use Capybara's matchers in the acceptance tests.
But why you should prefer to use the capybara matchers in the view tests ?
I was going to change the "prefer" to "always", but I don't see why you should do it, maybe only for consistency with the acceptance ones.
Don't you have duplication in the acceptance and view tests ? The view is simple template and you will test the behavior in the acceptance test anyway, everything else that need unit testing will be in helpers and modules, so I don't see the value in testing the views.
Explain difference between Capybara's negative matchers and should_not