No idea what leasing is like today but first tractor I had was leased and was a very good decision. It served our needs very well till the end of the three year lease and realized my needs need larger tractor. You might do well to see options there on renting to get idea of the ability of the different size.
rScotty comments on size is good info. Currently own three and first one of them is Kubota
M6800, (68 hp) basic two wheel tractor. Bought for farming row crops. Then bought Kubota
B2710 (27 hp) for mostly yard work. Mistake did not get front end loader with it. Last one if JD 5525 (91 hp) for more ability in the field and with fel. Oh it has cab and four wheel drive. Use the
B2710 with 55 gallon sprayer and mowing. Finish and rough cut. Use the
M6800 for some tillage (left row crops to raise only hay), some spraying and mowing. I put as many hours per year on the JD as the other two combined. Due to the cab, a/c and fel. In hay operation do a good bit of spraying and fel work. Use the JD for spraying due to cab on it.
As rScotty talked about smaller tractor taking long, yep. It is easy for say mowing you think well a four foot mower only takes little longer than a six foot. I think you will find it takes twice the time. It is easy to miss the over lap you need to prevent skipping streaks as you mow. The same is true with such as disking or leveling land. Depending on your ground larger slower is more stable than smaller running faster due to terrain changes such as holes, ditches and changes in direction.
Take your time, ask questions as your are, listen, think, and you will do well.