I remember older versions of Aperture retaining thumbnails when masters were deleted. Lots of people resorted to opening the package and deleting thumbnails and regenerate them to recover some odd 10-30 GB of space, and I also recall this happening for myself as well when I did a restore from Time Machine once (Time Machine didn't backup the thumbnails at one point).

I was thinking of clearing some cruft from my HD, and went into the Aperture Library package - according to Finder, it says my Thumbnails only take up 25GB, so I'm thinking that deleting and regenerating the thumbnails won't save me much space.

Does the latest version of Aperture actually remove thumbnails when deleting files now? Or am I just misremembering my thumbnail folder size?

I guess on a related note, does the iPod Photo Cache actually remove files from the cache if there is no device that syncs them? or does it keep them around incase you want to sync them in future?

Running Mountain Lion 10.8.2 and Aperture 3.4.3.