In recent years debate has centred around the roles which should be played by Wednesburyand proportionality in structuring substantive review, and whether or not the latter should come to replace the former. This paper argues demonstrates that there certainly are different kinds of substantive review, but in fact, within existing common law rationality review the courts already focus on precisely the same kinds of issues as they do under proportionality review. Any differences thus derive directly from the subject matter of the cases, rather than from any distinction between proportionality and rationality review. By focusing principally on the Wednesbury v proportionality issues the debate has thus, to some extent, become diverted from its main objectives. Both those who advocate proportionality and those who advocate bifurcation are concerned to enhance the clarity and predictability of review, while also maintaining the vital appeal/review distinction. But in fact neither proportionality as it currently operates, nor Wednesbury, currently has the capacity to deliver these desired benefits across the area of substantive review. It would be preferable, therefore, to move away from focusing on issues of classification, or the territorial reach of the different approaches, and to focus instead on the two key issues at the heart of all forms of judicial review, in this sphere and in many cases outside it, namely what in substance is alleged to have gone wrong with the decision, and how intensively that issue is to be reviewed, in order to understand better what the courts currently do and how that might be improved.