If there are things still not rendered, it's clear that a sleep is not the proper way to deal with 'em. It's like doing a sleep to wait for the return of an ajax call. If you believe it's about js loading, back in the day selenium had a method called waitForCondition that expected for a selector to exist before executing the script. I believe this can be achieved with capybara also, using evaluate_script and a 'until' loop.

So,imagine you're testing a table that's fully loaded by Ajax. I believe the implementation could look like...

```ruby
  describe 'fancy table' do
    before do
      # set some shit
      wait_for_condition('table#fancy')
    end
    # rest of spec
  end
```