I have tried several tablets, both with LCD and Eink screens, and consequently I have tested many different screen protectors.
There is no doubt that Doodroo's is absolutely the best, in all aspects.
1) SHARPNESS: First, unlike other products I have tried in the past there is no compromise of the sharpness, if there is it is really minimal but honestly I didnt see it. In all the others products that I have tried in my personal experience the characters were a little fuzzy, at least this is my feeling. With Doodroo I don't have this perception.
2) FEEL LIKE WRITING ON PAPAER : Honestly, even just touching the screen is pleasant, it seems to touch something that resembles paper or at least certain types of paper. The great thing though is writing with the pen, making writing a pleasure.
I have tested this screen protecor on my "boox note air2" this device already has a protective film that improves the writing sensation, but I have tried the device both without and with Doodroo, without it is still pleasant, but from my point of view with Doodroo is even better, which makes me think that the Doodroo film acts synergistically with the film below. Unlike the same, it is more replaceable if something should happen. The feeling of writing on my device with Doodroo is light years better than what I experienced a year ago with the Remarlable gen 1, personally we are really on another level.
3) PROTECTION: From what I can see putting the screen against the light, absolutely no imperfections are observed. My hand is a bit heavy but scratches or similar marks appear on the screen, if there is any line it seems to disappear when I clean the screen. Honestly on other screen protectors used in the past it is possible to observe different lines and curves that do not seem to go away.
I therefore wonder if the technology behind this product somehow favors the reabsorption of the pressure exerted, preventing the screen itself from being scratched.
NOTE
I am currently valutate if test the Doodroo screen protector with "supernote pen" with ceramic nibs, this because as i said it seems the Doodroo offer also a very good protection and not only a good writing feel.. i still need to choose but if i will do this test i will try to report my results and say if it could be dangerous or not.