[cardinalman86]

I don't think a round base would be very good unless you had a lot of excess weight, if it exists, and can put a few heavy blocks in the center to keep a good center of gravity and lower weight. you could also lower the base a little too, just to help u from tipping over. in this competition, it doesn't give you much of an advantage. if ur stuck on a circle design, but can't fabricate it, why not try an octagon, it will make it a little bit easier and allow for the same minute advantages as well.
I personally kinda like the square base design, but only cus it allows for so many wheel options. if u do it year after year it gets a little boring, so u can round the corners or random stuff like that, but it's probably the way to go.