[J.Warsoff]

Mecanum wheels will allow you high maneuverability options (e.g. strafing), which would indeed come in handy this year, since there are no humps or anything on the field. This can help get you around defending robots, or be a good defending robot yourself.

On the other hand, treads will give you much more traction, therefore giving you more pushing power, as you did find.

All of this is going to depend on what kind of robot you want to build. Defensive bot? Offensive bot? Maybe a little bit of both? Other things like how you shoot, acquire discs, and other factors will also be variables in this.