Never tried K789. Used to have K480 but found fixed angle of iPad slot too upright and sometimes iPad felled out. Needed to hit the keys harder than normal. Moved to K380 and love it. Much lighter and better to type. Recently bought MX keys for Mac and it’s the best. Comfortable keys to type on, slight tilt of keyboard is great and of cause having backlit keys are great. Wider and heavier than I like but best keyboard. Interchanging between MX keys and K380 depending where I am.