The writing experience of the DPT-RP1 is not great, but I have been using it for almost a year now and would never go back. The amount of paper that I have laying around at work now is minimal. I have created a virtual printer to just sent whatever file I am reading to the DPT-RP1.
Although there is no official support for Linux there is a very good python API developed by some guy, which works perfectly. Color e-ink would be nice to have for the next version, but I'm ok if only the stylus gets an upgrade.