I'm using the latest version of C1, but it's painful to use.
importing images, and transferring images to a new catalog are excruciatingly slow.
importing a few thousand images takes hours. simply launching C1 can take 15 to 25 mins. (there are now 80,000 referred images in my catalog)
I'm currently transferring 11,000 images to a new catalog, with the aim of reducing the size of my main catalog, hopefully helping it to speed up a little. it's averaging 2s per image. looking at Activity Monitor, C1 is transferring images at around 10 MB/s when my iMac 5K and connected disks can work **far** faster than this. C1 is using less than 1 processor when there are 4 at its disposal. the app estimates that it'll take another 9 hours to complete the operation (although the estimates are **never** even close).
painful!
C1 v11.2
OS X 10.13.6