I think it comes down to how many times you plan on crossing the the middle of the field in a match. I am currently thinking that this game will become more like 2010 where many robots had no reason to cross the bumps many times during a match. Some have said that you might as well make your robot able to cross the bump and bridge, but I think there are designs out there that could make the bump a reasonable sacrifice in order to make other parts of your bot better.
But, like I said, it will depend mainly on how many times you think you will need to cross the midfield. If crossing the midfiled is going to be a main part of your strategy, then I think the robot will need to be able to do both.
I created a pole for the number of times expect to cross mid-court to get an idea of what others are expecting. See:
http://www.chiefdelphi.com/forums/sh...ad.php?t=99676