Self Cleaning Roller Brush
As a new owner, I was amazed at how dirty our floors were. After about 4 times for the unit to run, I was cleaning the roller brush to find a lot of my granddaughter's hair wrapped around the roller. It tended to be concentrated with the notches in the rubber wipers (excellent design work!) so that I could snip it with scissors to remove it. I thought that it would be nice if there was a razor blade running the length of the roller that would automatically cut the hair so it would be deposited in the dust bin.
Also, at both ends of the roller, the hair collected. So, if the drive unit and the bearing ends were removable it would make cleaning easier.