Mecanum wheels are very nice for alignment of your robot even when the driver has not had a lot of practice time. I would imagine this year aligning your robot in order to gain possession of a ball would be important to some teams. Practicing gaining possession in a real-game situation is difficult for a lot of teams, so mecanum can be handy here.
Also, I always throw in my vote for don't believe that mecanum can easily be pushed around. Wait...am i part of the
majority on this vote??
