Edit: I set the app to "low resolution" mode and it's sped up. This means, like Illustrator 2014 and prior, the application just can't be run on a high resolution screen as is. Adobe, are you planning to do an updated render engine like Illustrator? If so, please hurry. This application is useless on 4k and above screens right now.
I'm using an iMac 5K with the latest OS, 4gz, and 32gb Ram. Moving and resizing objects on the stage is insanely laggy and slow no matter how little is on screen and how simple the object is. Panning is also slow. Drawing shapes is slightly less slow. Drawing with the paintbrush and zooming are as fast as usual. This was not a problem in previous versions. Anyone else having this trouble? Including a video of the problem: