As a guy who went out of his way to create a Chromatic keyboard, I can tell you definitively, its easier to play improvised music, and with landmarks provided by blue tape in my case, but could be colors or textures, I dont think it'd be harder to play written.
On the chromatic keyboard, a major key always looks the same, its 3 successive notes from one row followed by 4 from the opposite row. This symmetry makes everything incredibly easier.
