In Cubase Pro 9.5 the lower 3rd can be made much smaller than it can be in Cubase Pro 10.
Rather than being able to shrink the Lower 3rd Window to a very small size, in Cubase Pro 10 the Lower 3rd only shrinks down to a fixed point and then can not be made smaller. 
Being able to keep the lower 3rd on screen but very reduced in size gives the user more Project window to work with. As it is now, the lower 3rd has been worsened, not improved, by the latest update.