Given the current state of SimpleTest development it does not seem realistically that it will catch up with PHPUnit's features of measuring code quality or even to get code coverage measurement any time soon. However we have a need for these features to improve the overall code quality of Stubbles, but we can not afford to spend time for porting any of these features to SimpleTest and maintain them afterwards as this would bind a lot of our tight development time.
Therefore I propose to change our test engine from SimpleTest to PHPUnit, and to port all existing TestCase classes.