I took a risk and updated my iMac from 10.12 Sierra to 10.13.1 High Sierra. I encountered 1 serious problem. My Datacolor Spyder 3 monitor calibration tool failed to calibrate the iMac’s display color profile. Serious photographers and other graphic arts folks understand how important it is to properly calibrate your displays so that the color is consistent with prints and other displays.
I contacted Datacolor support and was told that my Spyder 3 was obsolete and no longer supported 😦 I had to buy a Spyder 5 which is compatible with High Sierra. They offered my a 25% discount and a digital coupon to extend my Adobe CC subscription by 90 days at no cost.
I really did not want to re-buy a device that we use a few times each year, but all in all this is fair.