I'm running an i7 with 24 gigs of RAM. 2018 ran acceptably fast. 2019 is unusable.
Unless one disables rulers, the erase and paint cursors become spinning wheels; most other functions are OK for me in 10.14.1. Mac is from last year, Adobe and Apple were each saying it was the others fault, I gave up and got a new machine to go with the new Photoshop. Meanwhile, PS 2018 let me move the center spot for rotate layer, 2019 does not, which is inconvenient. I do some work in 2018 and then switch to 2019. Also, 2019 doesn't always remember that I want to export as JPG not GIF. Sometimes it does....
I moved my preferences file so it would create a new one. That seemed to speed things up. As for the center spot for the transform tool, it’s off by default, but it can be turned on by clicking a small box on the toolbar. I have the same problem with exporting. It often doesn’t remember my preference.