[JJ_SO]

No. I don't use Photos at all. I just imported a small library (=catalog) after I created a new one in C1 9. It's a Beta-version and at first it crashed because I hit an "OK"-button in a dialog window telling me the catalog was imported - it's better to wait after all activities stopped. My second attempt is bit bigger and there was again that OK button but this time it didn't crash. Yet. 

 

The C1 catalog of the Aperture library is about 630 MB, while the library with all files has a size of over 9 GB. So I think, C1 can look into the library.

 

There was an information about what will be considered:

 

projects, folders, albums - but no intelligent albums, they would need to be converted (and that means it's a one way ticket... )

 

Crops, rotations, mirrorings (didn't know Aperture can mirror pictures...  maybe not)

Exposure, brightness, lights and shadows, definition, saturation, black and white (not sure what the last means - BW pics or black point and highlight recovery?)

 

colour adjustments are only approxmative.

 

Could be worse... I recommend us three Aperture users to give it a try - of course, it's really limited, but unlike Aperture Capture One still has a future.