Im still using Aperture and maybe now LR4 instead, to sort, rate, and do quick culls of stuff before exporting to PS5. It is much faster for workflow stuff, but it is an extra step in there, and im not sure which app is better for that extra step. Certainly Aperture seems to work faster and more easily, but doesnt have a lot of the nice presets which LR4 does (all of the develops above are LR4 presets).