Well, with an HST, you can go any infinite speed up to the top speed of that range. Say your in low range and the top speed is 5 mph, you can start off nudging the pedal real easy to get moving then push the pedal down all the way to start moving at the full 5 mph. Precision is the name of the game with an HST. Another thing, the hydro transmission needs to be operated with the engine at a high RPM, say 2k or more, in order to get adequte performance out it. Like any tractor, the higher you have the RPM's, the faster your top speed will be in either a certain gear on a manual tractor, or hydro range on HST tractor.
I don't know about you, but with my PR trans, I tend to run the RPM's around 1500 when I'm just doing casual work. That's the nice thing about a gear trans in that you don't have to have the RPMs up real high to get good performance from the trans. At that RPM, it gives a good all around speed in the 4 gears in B range, which is about the medium range. If I'm using the RFM at PTO speed than I usually run in B range and I end up running into the "too fast or too slow" problem such as you've mentioned. In the abrupt way that a manual starts off in high gear, it tends to rip the turf up if I'm in say 3rd or 4th gear. When backing up it's even worse, it will whip the wheels on the RFM around so fast that it rips the turf too. To back up smoothly, I have to downshift to 1st or 2nd gear, then flip it to reverse. This particular problem bothers me in that don't get that precision that one may be looking for when back up with the RFM, plus 1 or 2 tends to be slow for mowing after you start backing up so I find myself having to upshift so I can move faster. I feel that an HST tractor, with a low or mid range that has a top speed of around 6 mphs, would be a perfect grass cutter. It allows you to start backing up smoothly and then mash on the hydro pedal to immediately start moving faster. Anything above 6 mph to me is too fast to be cutting anyway so you feel the bumps of the ground too much and your cut quality decreases as you go faster. This in itself would be the main reason why I think my next tractor will be an HST model. While I love the fact that I can just putt around all day at 1500 RPM for casual work, most of my use is cutting grass and a HST makes more sense for that. The only bother is having to hold the pedal down for a while. Though, now that they have cruise control options I don't think it will be as uncomfortable.
So to answer your question, Yes, the hydro trans fixes the issue with the "too fast or too slow" problem that you sometimes encounter with a gear tractor.
