I guess I am the odd-man out here....I prefer the gear drive, BUT if you are not familiar with tractors, or you may have other, less seasoned operators using the tractor, an HST has almost zero learning curve, and will make negotiating the steep inclines you mentioned easier and less stressful for new operators.
I have an L3400DT and it is a beast for its size, gets me around the small trails on my property and through the woods relatively easily even with a wood chipper strapped to the 3pt.
I would avoid a TYM, I would buy a used Kubota before buying a new TYM. YMMV but I have founds parts availability, dealership support, and general troubleshooting knowledge to be awful due to the major model proliferation that TYM offers across a variety of resellers and re-branded companies (big boy, mahindra, branson, etc, etc, etc). Don't let the "largest tractor manufacturer" tag line fool you. My TYM service manual looked like it was written by a 4 year old, and it was a generalized "how you can" do something, the fluid capacities were wrong for every single sub component assembly, and contained zero part numbers or dimensions for service parts (belts, filters, bulbs, etc). YES, you can figure this stuff out, eventually, but if I tell you an engine holds 2.5 gallons of oil, and the dipstick reads full at 1.3 gallons.....which do you trust?