Please try AE in demo mode by downloading it from our site before you make your purchase.  Also be sure to see our support pages for details on how to use AE.  Most of the support requests we receive are answered in thos pages.

JPEG Original Exported By AE Differ From The True Original

A difference in the file sizes for your JPEG masters versus the masters actually exported by AE can happen for a couple of reasons and is normal.  The first reason can’t be controlled, whereas the second is configurable in AE.
  1. Aperture sometimes declares that the metadata in the original must be re-written (including some preview icons embedded in the image file).  This results in smaller image files than the “original” even though the image itself is a pixel perfect copy.
  2. AE does extra processing on JPEG images in order to properly handle location data that may have been added in Aperture and any orientation changes.  Specifically, when location data that has been added in Aperture is not in the original metadata the original image is re-created to include that metadata resulting in a new image size. When AE processes the JPEGs in order to add in the location data it maintains the image resolution/dpi.  However, due to the decompression of the original image and recompression there is a very minor loss of image fidelity.  Practically speaking one would never be able to visually see the loss in fidelity.  
So with respect to 2).  This extra processing can be disabled in the advanced options.  Alternatively, this extra processing is not performed if XMP sidecars are created for JPEGs (also in advanced options).   However if you are migrating to Lr note that creating XMP sidecars for JPEGs is not a good solution as Lr won’t read those in for JPEGs.
Also, with respect to 2) the metadata processing that AE performs can result in the loss of a specific portion of metadata in a JPEG called the "Maker Notes".  These are camera brand specific metadata tags and therefore not standardized.  AE leverages OS X's Image I/O framework for metadata processing which supports only a small subset of camera specific Maker Notes.  If the Maker Notes are important for you to retain  a workaround is to pick the lesser of evils:
  1. Accept the loss of the MakerNotes metadata, but get the location data
  2. Disable the orientation and location processing in AE’s advanced options.  You loose the location data that you added in Aperture, but get your metadata.
  3. Configure AE to create XMP sidecars for the JPEGs.  Lr doesn’t read them, but you might be able to find a workflow using exiftool or a Lr plugin that can merge the metadata and embed it back into the jpeg.  A good solution is presented in Embedding XMP Sidecar metadata into JPEGs.