My tractor size and capacity needs are similar -- 40 to 50 PTO horsepower in a utility tractor. For me, the decision of hydro vs. gear (and 2wd vs. 4wd) was entirely about how much I was willing to spend vs. the importance of the feature for my applications.
I certainly found an emotional draw toward both HST and 4wd -- there is no doubt they both provide benefits in certain uses. For me, however, spending $25,000 or more on a tractor wasn't an option. We have an unlimited list of wants (college for our children, fencing and stables for horses one day, remodeling the basement) in which we have to make trade-offs given our limited budget.
My 130 acres are flat to gently rolling, so 4wd wasn't a safety issue. While I'd love to have 4wd (would "feel" good knowing it was there), there are only a few real instances a year where I find myself thinking "this is a case where 4wd would really help." Even loader work isn't a problem most of the time -- a utility-sized tractor with fluid-filled ag tires and a bush hog mounted on the rear does pretty well. It easily drives into and scoops heaping bucket loads of clay, topsoil, gravel, heavy stone, and other materials. When digging or smoothing with the loader, the front wheels are often lifted from the ground as you put down pressure on the bucket, which means 4wd would become 2wd anyway.
That much said, I can't drive into the woods facing down a steep hill when the ground is wet, load a full bucket of firewood, and then back out uphill. 4wd would make this task easy. So in those few instances, I either load 1/2 bucket at a time, or I back into the woods and hand carry wood around the tractor to load the bucket facing uphill.
Similarly for HST, I would love to have it. It would make bushhogging in tight spots easier and would give more control and speed during loader work and grading. When I was honest with myself, however, I realized that the hours spent on my tractor were distributed something like this:
30% Transport (either going somewhere to do work or carrying things back and forth)
30% Bushhogging in open fields
15% Actual loader-engaging work (does not include carrying things long distances in the bucket -- see Transport for those)
15% Tractor idling (try not to idle too much, but I end up sitting and thinking about a task I'm working on, or hopping down for a minute to hook something up -- and those minutes quickly add up during a day)
10% General maintenance (includes PHD work, box blade work, etc.)
When I looked at those, I realized that while I knew HST would be an advantage in the loader portion (and a small portion of bush hogging), the vast majority of the time I didn't have my foot near the clutch and therefore wouldn't notice the difference.
When I put those doses of reality together, I realized that while I'd love to have both 4wd and HST, I wouldn't be willing to pay a signifant premium for them. I found that I could buy a new JD utility tractor (53 engine, 47 PTO HP), 2wd, gear transmission, and loader, from my local dealer for $15k, vs. $25k or more for similar size and power models from any manufacturer with 4wd and HST. For my land situation and my needs, I couldn't justify the extra $10,000.
If my topography or my usage were different, I would value those features differently. If I had to spend every weekend moving 25 loads of material from one pile to another, I wouldn't hesitate to add HST to my list of must-haves. If I had very hilly terrain, 4wd would move up as well.
I don't have any advice for you, but I've found that sometimes hearing how other people have approached their decisions can help you make a better one for yourself.
Parker