Power consumption is only one of the advantages of eInk - what's it like in direct sunlight?
I actually tried googling for this but most articles are very thin on details right now. There's a
technical paper I found but I couldn't figure from it whether it would work outdoors. It did say that the black looks purplish in bright white light but that was "tolerable for plastic card display application". Not sure what "plastic card display" means - smart cards?