Re: what makes a test great
This December, I watched three sets of tests at three different dojos, mostly lower-level, which for us usually means 5th and 4th kyu, though one dojo has started doing 6th kyu.
At one dojo, the 5th kyu tests were miles beyond the ones at the other dojo. I know that their sensei puts a lot of emphasis on test preparation, and what impressed me about these tests was that all of the testers clearly knew what the technique was supposed to look like, the basic physical principles behind it, and where all their hands and feet went. For me, that's what a good early level test is about: demonstrating an understanding of a specific set of techniques.
Jumping ahead to sho dan, that same principle applies, only more so. A sho dan canidate should be able to apply a wide range of techniques to a wide range of ukes. Sure, it'll look better if you just throw everyone's favorite uke around, but it's more impressive to me if you can adjust the technique to different ukes. The technique should be strong, but in a sensetive way. I've seen a lot of fast and flashy tests, too, and they're all right, but not the be-all and end-all.
That said, I can't stand to watch the really sluggish tests, especially when they're both sluggish and choppy.
Confidence and Competence are probably the most important things, and all that comes from practice (which should also result in a reasonable level of fitness). I find that lots of test-focused practice really does make the test look better, too, even though I think it's more important to keep up with regular practice.
I could go on, but I have to go to work.