Turbomachines having one or more flow guiding features designed to increase the performance of the turbomachine. In some examples, flow guiding features are designed and configured to bias a circumferential pressure distribution at a diffuser inlet toward circumferential uniformity, otherwise account for such low-frequency spatial pressure variations, increase the controllability of spatial flow field variations, or modifying flow field variations, etc. In some examples, a diffuser having a row of vanes that include a plurality of first vanes and at least one second vane having a different characteristic than the first vanes are disclosed. In some examples, diffusers have an aperiodic section including one or more biased passages for biasing a flow field. And in some examples, turbomachines have flowwise elongate recesses in one or both of a hub and shroud surface.