Rat,
NOW for the last time I am NOT an HST HATER!!! I just don't believe a person HAS to have one. Yes they are nice to have but you certainly don't have any less of a tractor if you don't have one. If you will read my posts you will see that I have numerous experience with hst driven machines. Most of my life has been spent on the seat of tractors or heavy equipment. I think this has already been pointed out many times.
If you will look at the posts I think you will see that I have pointed out already that if you are buying a tractor just for multi-use around your house or small acreage and not raising crops, etc. then an hst will be fine if you want one and there are no real disadvantages. If you are farming though, big disadvantage. As far as getting work done faster I've used both and while they may be a little more convenience wise a person that knows what they're doing it won't matter if you are on an hst or a gear tractor you will get the same amount of work done just as fast. You may get the work done faster on an hst if you are not experienced but a good operator will keep up with and do just as much work with a gear tractor, especially with the power reverser. Once you are familiar with equipment you make the adjustments just as fast as you would on an hst. Most guys that I see posting on here anyway say that time isn't an issue they just want to be able to use their tractor to do the job. Most guys enjoy using their tractors. From that standpoint it's certainly more fun to be shifting gears and moving levers to get work done rather than just pushing on an accelerator pedal. And others want that convenience and that's ok I'm not bad-mouthing hst's. As have already been pointed out there are numerous advantages to a gear tractor over an hst and vice versa. As far as speed varying greatly that will simply not happen unless you have too high a gear or not enough horsepower, again experience knowing how to get the tractor geared and idled at the right speeds.
As far as farming goes many of the guys here have expressed a desire to do farming with their tractors. I take care of almost 400 acres with mine and the Super 90. It pulls all types of machinery where a gear drive is needed so yes there are guys that buy these tractors for serious farming. I didn't do a census of farmers here for tractor types like is done in CA, but I do know alot of guys, that farm thousands of acres, that have them as they are easy to get around the barns and such and for doing smaller jobs.
As far as your comments about losing if you are on a hill that is simply not true. The power reverser will do the same job your hydro will do. All you have to do is pull back on the lever and the tractor will go into reverse gear just like stepping from the forward to reverse pedal. All you're stopping anyway with the hydro is the transmission. I sure don't want to rely on my transmission for stopping purposes as that would be pretty hard on it over time, that's what the brakes are for.
All in all an hst is a great transmission, no doubt, but it certainly isn't the golden calf that is so often exclaimed. For a beginner it's a great way to get started driving a tractor. For an old pro it's a great convenience if you don't want to fiddle with gears and levers and such. If you know what you're doing though all you're gaining with the hst is convenience. For some of us you lose a few things that we like. As far as speed, etc. goes in doing jobs you don't lose anything you just have to work a little more operating the tractor.
To sum up so we don't misunderstand each other I agree that an hst is a great tractor to have. It gives you alot of convenience and less operations to perform to do the same work. For some applications it's the cat's meow. For others it's a hinderance and not applicable. While an hst should certainly be considered it's not an absolute must to have. You can still do the same work, just as fast, with a gear tractor, it just takes a little more effort. Just because I point out the other side it doesn't mean that I am against them. Most people though say that the hst is the only way to go and there are other choices that are just as good, it just depends on what you want to do.