When testing a new product interface, we at Websystems have our ears out for comments that sound like "it's complicated" or "I can't figure out how to do this."
For us, when these comments are made repeatedly about a feature or a page in AceProject, it means we've made a mistake in our design. While we work hard on getting good, usable documentation for AceProject, our goal is that our users don't need to consult it when building their projects, updating their tasks, and going about their daily activities in the system. We think is filling out a time sheet should be self-evident.
Moreover, even if it's really difficult for the developer, he will work on making that feature simple and easy for the user once. The user, on the other hand, will use the feature many, many times. So it's more profitable to invest development time once, since it will save a lot of user time in the long run.