Mecanum vs. Tank Drive?

[Taylor]

Great question!
There are two schools of thought regarding mecanum wheels. One is that mecanums are an easy way to gain an extra degree of freedom when driving (easy as compared to swerve). It does have a bit more complexity than a standard 4 or 6wd setup - more refined versions of it require use of a gyroscope. However, this does allow a team to get many of the translational properties that swerve allows, at a reduced cost and a fraction of the resources (labor, motors, programming, electrical).
Another view is that mecanums are a lesser drive system - by virtue of the rollers on the wheels, they are subject to heavy defense, and cannot play defense themselves. This view is usually the more loudly proclaimed, usually by people who heard this view from somebody else, and by people who have no direct experience with mecanums.
I will say that a number of high-end teams have experimented with mecanum drives and felt they have found a better solution elsewhere.
I will also say there is a stigma with mecanums, with questionable merit, and some teams say they would not pick a mecanum robot to ally with in eliminations. However, I have noticed that the people who proclaim they'd never ally with a mecanum robot, aren't usually in a picking position.
The general rule of thumb is if somebody doesn't know how to spel "mecanum" then their opinion is mostly based on hearsay.
Welcome to Chief Delphi!