that depends on what you want to do with your bronc
I didn't get sidewall specs on the maxis but the cooper has a 3 ply sidewall for the sizes I found which is better then the typical 2 ply sidewall which when on wooded trails it doesn't take much to poke through 2ply.
the maxis seems like a more open self clearing design that would be beneficial for deep mud or snow, but the cooper would have a quieter street noise while still being almost as capable in mud and snow.
if those don't swing you one way or the other look at the price tags.