The quiz reports have not been substantially revised since at least Moodle 1.6. This means the conversion to roles and capabilites was somewhat superficial, and the interface has not been converted to formslib. Elsewhere in Moodle there have been improvements that these reports could benefit from, for example the moodle_url class, and some of the features implemented for the new gradebook reports in 1.9.

Bringing the quiz reports up to the standard expected in Moodle 1.9/2.0 would greatly simplify long-term maintenance of these reports, and so reduce costs long term. The will also mean that people who learn how to write Gradebook reports will then easily be able to write Quiz reports, and vice versa.