When Camera Bits announced PM6+, my initial reaction was that I would not benefit from the catalogue feature since I use the catalogue feature in Lightroom. I was wrong.
I still have one large LR catalogue. Searching for images is slow and often I cannot find the images I want. Now that I have all my images in the PM6+ catalogue, I have powerful search features that make it a snap to find images. Additionally, If you have multiple LR catalogues, such as a catalogue for each calendar year, finding an image that you took years ago but can't remember the year, would be a hassle.
PM6+ catalogue features are well worth the small license fee.
