Several studies have reported that fast reading and particularly skim reading is slower on backlit LCD eReaders as compared with printed paper. A reason suggested for this difference is the mismatch between LCD display brightness and ambient brightness. When eyes look away from the text, either for a pause or short thought, the large difference in brightness causes a small delay as the eyes make an adjustment. This result in a reduced reading rate.
Similar studies comparing reading speed with E Ink eReaders against printed paper have not yet been conducted. So we cannot say which is the best ereader for fast or skim reading. However, as E-Ink displays are designed to simulate more closely printed paper it is expected that reading on E-Ink displays would be quicker as compared to LCD displays.
Integrated reading tools, such are phrase search, dictionary, Wikipedia, highlighting and annotation help to close the gap between eReaders and printed paper.