easy to maintain
                Use powerful WebDriver API to run tests on many browsers: IE8+, FF, Chrome, Safari, Android, IOS.
                Assertions are picture comparisons. Only have to update reference pictures.
            
reproducible and rapid testing
Run tests periodically with Jenkins/Hudson. Soon, use proxy to speed up and improve reproductibility of your tests.
more precise than human
Detects any issues with pixel-perfect picture comparisons.
Write your scenario (example here)
Run it forever with Jenkins/Hudson !
To see how writing test is so simple with Eagle, take a look at this example.
'Type-Search' : function () {
    return eagle
        .findByCssSelector('.inpt input')
        .type('engineer')
        .end()
        .findByCssSelector('.inpt span')
        .click()
        .end()
        .sleep(2000)
        .captureElementByCssSelector('.jobform-ui','Screenshots/Orange','search-form')
        .captureElementByCssSelector('.joblist','Screenshots/Orange','results');
}