I use my tractor in the woods as well as in and around my yard. I have a slight slope. I traded tractors mainly to get a HST transmission. Best decision ever. Gear is not bad by any stretch, but I much much MUCH prefer the ease of use and friendliness of the HST. On hills I can't recommend a gear tractor, although I'm sure there are plenty who use gear on hills and wouldn't change for anything.
In cars and trucks, I only want a manual transmission. On a tractor, I want to focus on the task, not the transmission.