[Jake M]

Actually, we've had a fair bit of discussion and experience on this point.

For us what we found was...

PROS:
-If the board is removable, it's far easier to work on the board, say, to replace wires, reconnect wires, replace any components that might get fried, etc. than it is to do when you have to reach around inside the frame of the robot.
-When all the big electronic components are compacted together, the system is a lot easier to troubleshoot (by testing connectivity and voltages, and plugging and unplugging, etc.) and problems are a lot easier to diagnose than when components are spread out all over the robot
-It also becomes easier to organize wires and components when they're all compacted together.
-When the board can be removed and remain fully functional, one can do a very large amount of programming without actually needing the physical robot, meaning mechanical work on the robot and electrical/programming work can occur simultaneously and separately.

CONS:
-Obviously, not all programming can be done without the physical robot.
-When boards/boxes are used and care is not specifically taken to design the board around the robot, and to design the robot around the board, the board can be very, very difficult to remove.
-Once the board is built, it becomes very difficult to add new components after the fact. Thus, you can either allow a lot of extra room, wait to design the board until the last minute, or just design it and cross your fingers that you won't need more stuff later.
-With some designs (mostly just with a box design), it might actually be more difficult to get at some of the components.

That's about all that's coming to me at the moment, though there's probably a few more. Keep in mind that I am a proponent of the removable board design, so I'm probably a bit biased. Plus, considering the fact that no two teams are alike, what is a plus or minus for our team is not necessarily so for others.