A client that's unhappy for a reason is a problem, a client that's unhappy though he or her can't quite put a finger on it is worse. Chances are there wasn't collaboration, communication, and checkpoints, there wasn't a process agreed upon or specified with the granularity required. It's content strategy gone awry right from the start. If that's what you think how bout the other way around? How can you evaluate content without design? No typography, no colors, no layout, no styles, all those things that convey the important signals that go beyond the mere textual, hierarchies of information, weight, emphasis, oblique stresses, priorities, all those subtle cues that also have visual and emotional appeal to the reader.