EInk displays are very cool in their specific use cases, but not where the screen need refreshed frequently.

Pros:

• very crisp display. Work great in full sun.
• text usually looks very good on these displays
• 0 power usage when not refreshing the screen.
• display remains as-is even if power is removed. Potentially for hours/days

Cons:

• expensive vs LCD
• refreshing the whole screen can take several seconds
• limited to B&W or sometimes one additional color
• not visible in the dark or in low light.

Some good use cases:

• Price/ID tags
• Thermometer or other slowly changing sensors
• Clocks (without seconds)