I'd like to see some actual data to back up the idea that 30 seconds a side is enough, as everyone's mouth and eating habits are different. I appreciate how nice it is to be able to say "brushing takes 2 minutes...ALWAYS", but that just seems too simple to actually be the case. I'd like to see a study done to compare mouth cleanliness of those who use a brush with the 30 second per quadrant buzzing and those without.