Basic functionality is good, but keep the limit to 25 questions. Go beyond that and you have to "daisy-chain" your quiz. ie multiple short quizzes tied together. And when you do that, you have to write a bunch of code to carry forward the results of the earlier quizzes. Wouldn't be so bad if the documentation covered it, but the docs are very poor - mostly basic functionality, and Chris hasn't been on the forum in 4 months so getting an answer there doesn't work.
And most frustratiing, the s/w is buggy. When you make a change to the quizzes "top level" parameters, like changing which script is used for scoring, half the questions reset, and you have to re-enter them again.
Chris does offer a 10 day money- back guarantee, but since the quizzes are written and working, I'll hang on to it. But I also won't be using it as much as I would like to.
Since it's been some time since an upgrade, and some time since the forum was answered, this seems to be an abandoned extension.