[Kevin Leonard]

I've seen one exceptional implementation of Mecanum wheels in all of FRC ever- and that is Team 2052, KnightKrawler, as has already been mentioned in this thread.

I've also seen a few robots where the ability to strafe gives them a marginal benefit over a traction drive- 126 2013, 58 2012- where the ability to strafe gives them an ability they wouldn't have had otherwise.

I think all of these robots, barring perhaps 2052, would have been just as good or in some cases better with a traction drivetrain. However, it depends on the strategy and role your robot intends to play on an alliance.

If you were a cycler in 2013, a Mecanum drivetrain can be fine, sometimes even a good thing.

If you were a full-court shooter in 2013, where your entire strategy revolves around reaching a location and staying there for the match in order to score points, you should have a drivetrain that allows that.

In 2014, any robot that could get easily pushed across the field moved down the picklist, purely because that makes it more difficult for them to score. If you drove that same robot like 33, you move back up the picklist because your driving is fantastic and makes up for that to a degree.

If your robot exhibits negative qualities in a match, it will get penalized- not because it specifically has a certain mechanism on the robot, but because the robot doesn't do what needs to be done, and that could cost my team the regional.