HST transmissions are good for where you need very incremental speed control - garden tractors, combines and other harvesters (corn, beans, etc), etc. - very popular. However, on the higher HP machines, the HST tends to use a lot of hydraulic fluid. We sold it by the barrel during harvest season (I used to be a tractor mech - worked my way through college in John Deere dealerships). You may notice that if you some Costcos sell a lot of hydraulic fluid - that is because a lot of compact tractors now have HSTs. An HST can also be jerky - especially with larger machines - because of the weight of the machine. For a farm tractor where you are just going at a steady speed such as during plowing, discing, etc., most farmers prefer a geared tractor as it is more fuel efficient and puts more power down to the ground. For a compact home tractor an HST would be good as you generally are not out plowing hundreds of acres, you are moving around the yard or small acreages, moving back and forth, and so on - the ability to almost instantly incrementally moderate speed without changing gears is helpful, as is the ability to change direction easily (although a lot of geared tractors come with a feature to do this too). Generally you are not too concerned about fuel efficiency with a home compact tractor either as you a 10 to 20% difference doesn't mean hundreds of gallons in one season like it does for a farmer with large acreages.