The older version may be more comfortable for your eye, but the new version is more useful. You have your own account to manage your mangas, comments, questions and topics.
I do believe the new version will become better & better and provide more facilities for the users.
Well, "zoom in" would help for the dark screen.
Actually, the new one is more comfortable to my eyes x). It's prettier and I have so difficulty whatsoever with reading white on dark blue. Not sure why some do. Maybe it has something to do with your monitor's brightness level or something.
Moreover, you can keep your favorite scenes of the manga you like by using the "bookmark". I bet you will love it. (>_O)v
i like the older version so much better....