I'm the kind of guy that can usually walk and chew gum at the same time but if I think about it I'm probably going to bite my tongue or trip over my feet or both.
I can chew gum and march in close order drill while playing a snare drum. I was also entertained by Egon's comments (usually am) I was pointing out that coordination is not my limitation. I have plenty of limitations but coordination isn't one of them.
Almost anyone can operate the FEL by the numbers one control at a time doing most anything with no problem with a gear tractor. With good coordination you can move the tractor, steer, feather the clutch, modulate the brakes, and raise or lower the bucket while curling it all at the same time. I have seen really good operators, true artists, do really well with a gear tractor.
HST allows the artist to do even more better and faster. HST enables someone with lesser ability and or experience to be more productive than they can be with a gear tractor in all tasks requiring close maneuvering and or lots of direction changes.
I make no claim that geared tractors in the hands of the truly competent can't do really well but for lots of close in work HST will be a better choice for almost anyone willing to learn to use it.
I rarely plow and don't disk much but I do move a lot of dirt, juggle round bales, move materials wth pallet forks and so forth. I have TNT and a hydraulic raise and lower scarifier on my box blade which enables me to easily do what is totally beyond most manually adjustment setups, at least in ease, speed, and precision. A geared tractor is not well suited to the kind of work I usually do. It isn't whether or not a geared tractor COULD be used to do my work it is whether or not it is the best fit. You can drive screws with a hammer and with practice get good at it but that doesn't make the hammer the tool of choice. If you have mostly tasks that a geared tractor is suited for then lucky you, you may save a buck.
The only time I depress my clutch is to start the tractor (safety switch requires it), engage and disengage the PTO as gently as possible, or select a different range (low, med, or hi) and I use my brake pedal even less except for engaging and disengaging the parking brake feature. Easing up on the hydrostat pedal slows the tractor. Abruptly letting up is equivalent to putting on the brakes. It is hard at most speeds to take your foot off the hydrostat pedal and get it onto the brake pedal before you are stopped or nearly so by the hydrostat.
I have yet to see any advantage offered by a gear tractor when relating it to my use. Others may find gears to be just exactly what works for them.
Pat