[Jared Russell]

COTS drivetrain options are so good and so affordable nowadays that unless you (a) already have a tried-and-true design in your back pocket, or (b) decide you really need something out of the ordinary to execute your game strategy or robot concept, you are almost certainly better off going COTS (IMO).

All the same lessons that can be learned or taught with custom drive trains can also be learned or taught with custom manipulators and scoring mechanisms, and the latter is far more likely to set your team apart in the competition.