As a side note, there is also OhUI (https://github.com/arcanis/ohui, i'm the author) which has the same goal than blessed, but a different api (dom-based) and codebase.

Blessed is great, but I had some performance issues with really fast updates, so I made OhUI, which tries to minimize as much as possible the repaint zones. I think it is pretty efficient at this regard.