Unfortunately, the Aperture and Lightroom data models and workflow are different enough that Lightroom really can't import everything that you've done in Apertu

Unfortunately, the Aperture and Lightroom data models and workflow are different enough that Lightroom really can't import everything that you've done in Aperture. Quote from Lightroom page: "migrate their images and key metadata"... It also doesn't support the non-destructive workflow edits that you've applied to your (potentially) tens of thousands of images. If you import them, all the edits become baked in.