My system's framerate drops into the 10-20's when Photoshop does anything (move canvas, paint a line, add text, hide a layer, anything) and even affects the system when minimized. I can tell as much because I have a 360Hz monitor with a built-in framerate display. Photoshop drops the system from 360 FPS to 10 FPS and the cursor moves very choppily and slowly.
After a while, Photoshop disables all click-and-drag operations elsewhere in the system. Closing the program re-enables it. How is this even possible? This is the next thing to being "virus level" bad software.
Updates made to dialogues (color picker, layer effects) are sometimes not reflected live on-canvas until the dialogue is closed – meaning you can't see the updates to the image as you make them (e.g., adjusting drop shadow, stroke, gloe, etc.). Seems to also require restart to fix.
This is the third time I've asked this question — does Adobe invest no money at all in QA testing before releases are published? This ain't freeware y'all... this is premium software for premium pricing. Please stop releasing program- (even system-) breaking software.