Single or 2 speed gearbox?

[audietron]

I have looked through the game and came up with my own version of a robot that I would find optimal. Except the only thing I am on the fence about is the drive gearbox.
I can see using a single speed geared toward 11 fps for simplicity and compact design but I can also see a 2 speed for getting over things fast while low gear is for pushing and if the robot gets stuck on a defense.
(Optimally a 7 fps and 17 fps 2 cim gearbox)

What are your options on a particular gearbox design and what is your team most likely doing?