It generally is stable. However, some operations often crashed the app (large metadata write backs) and especially the Google Vision integration was wonky for me (not a critical element but still, if you do it on a large set of images the app will crash both on Mac and Windows. IMatch has similar integration and so far I haven’t had a single crash and also way less spinning beachballs during large operations. I don’t like it when apps make the whole system unresponsive when they are doing operations, they should have load balancing so there is still some responsiveness at any point.
But I wholeheartedly recommend both IMatch and Photo Supreme. Best DAMs in town… and on the Mac Photo Supreme is your only good option.
I agree that they are not cheap but on the other hand you buy a perpetual license and I think you can easily use them for 2-3 years without a real need to upgrade. They are so much more efficient in handling and managing your photos that you quickly earn the money back with time saved. But it also depends on what workflow you want… if you want to edit in DXO, Photoshop or Affinity Photo I really recommend getting separate DAM software, with Lightroom and Capture One you need to see for yourself if you need all the extra bells and whistles. I can’t stand the Capture One DAM part for example.