I've experimented with a few e-ink modules over the past years, and also with commercial shelf-edge displays at work using this tech. There's a wide variety of black&white, grey-scale and 3-colour units out there, but this panel really stands out as the first readily available 7-colour I've come across. Setting this up is trivial, you just pop it on the Pi GPIO header, download the library, job done. In use the refresh rate is comparable to other panels of this size using a generic conroller. The colours aren't hugely saturated, but look great particularly under bright lighting. Awesome piece of kit!