I think it really depends on the game.
I personally found the bumpers a little bit of a nuisance when it came to getting up the ramp and collecting balls. If next year's game requires climbing something steep I don't see them as an advantage.
I don't think they really protected our robot that much, seeing how we only had them on the sides and we only got hit on the front and back. Which oddly wound up being the only parts of the frame that didn't get bent...
