Myself, I have 5 acres of land, a garden and I mow with riding mowers. I bought a great 18hp diesel--Satoh with a roto tiller--540 pto. The 540 pto speed is why I do not mow with it, the riding mowers are much faster. To exceed the 540 speed with a mower or bush hog is not what I wish to try. The roto tiller at 540 pto speed is enough for the tractor. My tractor I paid $2500.00 cash money and its in great shape. If I had a bigger home, than maybe I would reconsider the tractor size. I am pretty much set as far as landscaping, just need some minor work that a smaller tractor can handle.
The tractor on the left is the one I use. Its around a late 1980,s model.