Welcome to TBN.
This is the most hotly debated subject on this discussion board. This is your warning, you are apt to get many strongly voiced opinions.
I'll give you the bottom line up front. Buy what you are comfortable using.
There are a couple different gear trannys, "basic" requiring you to come to a complete stop and push in the clutch to change directions, and the "deluxe" depending on manufacturer, refered to as "shuttle shift" or "power reverser" etc. These allow you to shift from forward to reverse w/o stopping or clutching.
To my knowledge (I could be wrong here), all transmissions require you to stop to change gear ranges (Hydros have L, H or sometimes 3 ranges). The one exception might be the Class III New Hollands.
here are the major pros and cons as I see them.
Hydro: Pros: ease of changing direction, infinite speed, resale value, safety(debateable). Cons: initial cost, less efficient (~5% +/- less available PTO HP)
Shuttle: Pros: ease of changing direction, resale value?, Cons: requires stopping to change speed
Basic gear: Pros: Cost, Cons: less user friendly
I don't think anyone will disagree with the pros/cons I've listed. But what is debated is how much of a difference there is regarding the qualitative pros/cons, ie safety & user friendlyness. Some say they feel the hydro is safer because if you step off the pedal, the tractor stops. Some feel it isn't safer because if you abrouptly step of the pedal, the tractor stops too fast, or they are used to pushing in a clutch & a brake to stop a tractor. Purely personal preference.
You say you've mostly used a hydro. How did you like using the gear tractor? Did you feel it was as user friendly (for you)? Do you feel you'd be as productive?
When you factor in resale value, the cost issue for a new machine becomes a matter of a few percent of the total value of the tractor (comparing Kubota w/ Hydro vs. Kubota with gear), so my recommendation is to buy based on your comfort level, not cost. Especially considering all the low interest financing deals to be had. If you were looking at a used machine, buying a gear tractor can make a more significant difference.
Also, if a gear tractor is for you, that opens up many options as far as manufactures go beyond Kubota. Mahindra, Kioti, Branson, Century etc. These can offer even more savings.
Try using the search function. A search on "hydro vs. gear" is sure to turn up a bunch of posts.