I've always tried to give my clients more than they are expecting, many of them don't even realize what small things I've done to make the shoot and images better. I've always been one to show my best, the competition out there at the high end is all about the best. Showing someone you've never worked with average can go one of two ways, if they were expecting better, you don't get the job, if they are happy with what they see then you do. Showing average is a risk. On the other side, many photographers can come up with 10-15 great portfolio images but can't deliver that quality consistantly, which is where they end up disappointing the client. In this case, showing the level of average quality protects the photographer, in the event that things don't turn out well.
I thought what was posted was well done though, there are definately ideas in there that can be used.