G-force.
I could not agree more. I personally spent the full two weeks on my answers. I wanted to make sure that they absolutely reflected my desire to become a pilot and also reflected my suitability for the role/BA whilst making sure that it was written grammatically perfect and professional. I then had my older brother (being a doctor and highly literate) proof read it for me and make any adjustments he felt were necessary.
Spending just 1 hour on this application just doesn't seem entirely wise to me. This may or may not have been the reason why some people did not make it to the initial interview stage but either way, it makes more sense to spend as much time on the application as possible to give yourself the best possible chance.
Also, as G-force said, the initial application plays a big role in the whole assessment particularly at the final stages. For eg. If you were an interviewer and you had two applicants who performed equally as well in all aspects of the the assessment process and ticked all the boxes in the interview but they couldn't particularly remember your face etc. What do you think will be the deciding factor?