Some pianists report greater ease with memorisation, for example:
‘I was very surprised by the difference it made in my ability to memorise music. Because everything was more natural and less awkward on the smaller keyboard, it was easier for my hands and muscles to learn the patterns and commit them to memory.’ Nicole Halton, New York, USA.
The first pianist to purchase a DS5.5® keyboard, Linda Gould, commented: ‘Sight-reading probably has the most dramatic effect. When you are sight-reading difficult music (especially with other chamber musicians) you do not have the time to work out the easiest way of playing a passage, you just plow through it. I am talking about pieces like Brahms Horn Trio, Saint Saens Piano Trios …(http://www.steinbuhler.com/html/linda_gould_s_testimony).
It is possible that sight-reading would be more dramatically affected for people with the smallest hands, particularly if there is also poor flexibility between fingers, to the extent that many basic chords cannot be played on the conventional keyboard without dropping notes. When sight-reading, such a pianist has to make instant decisions about which notes to omit or how to get around a passage which is difficult or unplayable.