Iris-opt seems to be pioneering ChLCD so there's probably some bias here, but I'd never heard of ChLCD before and it looks great.

There are some more examples here https://www.genetouch.com/page/news/show.aspx?num=74&lang=US

Is Spectra 6 the current top contender from E-Ink? I can never figure out their lineup. Not Gallery Plus?