That really depend on what you want to do. A lot of us here are tractor hobbiests and we live to play with tractors so bigger is better. But if you are not one of those, and you really are looking to do some stuff around the house and save your back from labor, then there is nothing the small machine won't do that the bigger machine will do. For mowing they are both going to be about the same speed, the SUB-CUT class machines may be a bit faster simply because some turn tighter and the fact that they sit lower so they can often get under ornamental trees than a small frame CUT will get under. Both sizes of machine will push or blow snow. Both offer similar size blowers and both can be had with either front or rear mount snow blowers (rear being about 1/2 the price as front mount, but far less convenient). Light landscaping is easy enough to do with either machine, the smaller machine might take a bit longer to do some tasks, but if you are just doing stuff like moving mulch around then there is no big handicap for the smaller tractors. The SUB-CUT will lack in lift HEIGHT so if you are trying to dump a load of mulch into the back of your pick up truck, you might have some problems doing that. At 4 acres, you could easily use a Sub-CUT and you could probably just as easily justify a small frame CUT. I guess you are in the fence (at least in my mind) in terms of size. So perhaps it is more a matter of desire and budget than practicality. (based on LIGHT landscaping)