I'm a well known grump...
- Edit My Images
... I'd also quite like to export all the edited versions from Aperture, although that can probably easily be done to an external drive.
I do like the idea of TIFFs for higher rated images, and JPEGs for lower rated ones. That ETA time though is a hopelessly optimistic estimate; this trial run has been going for about 3 hours now (exporting to an external drive on a standard USB port, 2014 era), and is now estimating the ETA as 12 hours 40 minutes! There does not appear to be any way (that I can see) to run it on a subset, eg a set of folders... although, I suppose you could export that set of folders as an Aperture Library and run ApertureExporter on that.
One thing I had not quite appreciated is that ApertureExporter requires Aperture to work, so you definitely have to do this before Aperture stops working, ie before MacOS Catalina.
I have noticed various oddities in relation to file sizes, eg exported JPEGs being different in size from the sizes reported by Aperture. At the moment (since most images have had some adjustments in Aperture) I'm getting two files from each image, eg CB67A01A.jpg for the original and CB67A01A_WithAdjustments.jpg for the adjusted version. For that image, Aperture reports the file size as 1.95 MB, the original pixel size as 3300 × 2207 (7.3 MP), and the adjusted pixel size as 2154 × 3221 (6.9 MP)... it has been rotated and cropped (as well as straightened, 6 dust spots removed, and a Levels adjustment). ApertureExporter's "original" version is reported by Finder as 2 MB, and the adjusted version is 1.7 MB. While the file creation date is today, the Content Created date reported by Finder is March 1967, and it shows the device make and model as Plustek 7500i (my scanner). Interestingly, Finder shows the Content Creator as QuickTime 7.6.6.
At the moment, I think I'm probably going to pay the price to get the full version of Aperture Exporter, not least as an insurance policy. I'm hoping that for most adjustments, Capture One Pro will do a reasonable job. However, I believe that C1Pro does not transfer spot, repair and clone adjustments. Since the source of much of my library is from scanned negatives and slides, some over 50 years old, there are a lot of images with those adjustments. For them, I may be better ignoring the C1Pro imports and using the ApertureExporter adjusted versions instead. I haven't quite worked out how to do that yet.
Once this run is complete, I'm planning to do a trial import from my 2019 folder in C1Pro. I hope that will let me make up my mind before the current offer on the C1Pro Fuji version expires at the end of the month (TBH I think I'm pretty much committed to paying up now!).