8/10 functionality, but 4/10 discoverability for new users.
The Lumetri eyedropper is powerful but can be finicky. It often samples a single pixel, which can result in noise (getting a weird color because you clicked a random bright pixel). Tip: Hold the mouse button down and drag while sampling to average the colors in a small area for a smoother result. eyedropper fill premiere pro
If your 4K footage is lagging, drop your Playback Resolution to 1/4 or 1/2 . The eyedropper will still sample the underlying color accurately. 8/10 functionality, but 4/10 discoverability for new users