@ranOOm We played a lot of matches with wide robots, and even the pilons (5225a) and wof (8825S) last season were quite wide. Being wide doesn't drastically improve maneuverability on field, and toggling flags with a 30 wide or 25 wide should be roughly the same - it's not going to be harder or easier on either. Being a tank won't slow you down, a 200rpm drive will still get to ~190rpm on each pretty easily.
At my competitions, if you had a wider chassis, you would have more attachments on them, which would be more weight, which would, in turn, make the robot heavier. As a result, you would be slower. I wasn't trying to say that a standalone wider chassis was slower, just the more attachments you are (probably) intending to put on there.
If you have a wide chassis, but not much on it, then that's more weight on your robot you don't need.
Hope this clarified my original statement.