Rob,
I am not saying that the tractors are the same size, I am saying there doesn't seem to be that much difference in where you can fit in yards or lawns. I have found that in most instances my 4520 gets close enough to cover 90% of the jobs I have. Sometimes I could use an X7XX series with a rear tiller or cart but it is suprizing how few places I can't go with a 4X20 tractor. An example of what I am referring to would be comparing my 110tlb to a 410 extendahoe. While I may be able to get in closer with the 110 the 410 extendahoe can reach about twice as far. In some cases the 110 wins and others the 410 wins I would bet most of them will work the majority of the time.