I also seriously considered both the 1430 and 1445 before settling on a (used, but like new) 1845 for steep terrain tree and brush removal for fire mitigation at 8000 ft in Colorado.
Power was one consideration, as non-turbo engines tend to lose over 25% of sea-level rated power at such altitude, by starting at 45 I still have nearly 35 available. The three cylinder 45 HP Deutz is also inherently smoother than the two cylinder 30 HP model, especially at low speeds.
The main reason however, was as Charlie mentioned, the Brake Tender failsafe large-diameter hydraulic disc brake system developed and approved for mining equipment use. Whatever else one can say about OSHA and MSHA type regulations, they are usually way overdesigned for "normal" applications. Only the PT-1845 and 1850 "slope mowers" are available with this system.
As my operating environment was to be mainly on long rough 20 to 35 plus degree hill sides, I wanted to make absolutely positively sure I would have fully capable four-wheel brakes that I could mannualy or have automatically apply in the event of a sudden engine or hydraulic hose-burst type failure.
I have not had the (miss)fortune to put them to the test in failure mode, but they have worked well in manual mode, and also automatically apply whenever you shut engine off so you do not forget. One slightly annoying aspect is that if you momentarily lug the engine down such as in digging with the loader bucket, the hydraulic pressure that keeps the brakes released can drop below the threshold and apply them. You simply flip the lever back to the release position and continue on. This does not happen often.
On the plus side for the 1445 however, it comes with higher torque wheel motors, larger and heavier duty tires, more ground clearance, and higher capacity and reach lift arms. It (and all other models above other than the slope mower series) has fail-safe internal "wet disc" brakes on all four wheels (I think) that work in a similar manner, but are not as capable of bringing a loaded or moving machine on steeper terain to a quick halt. The 1445 is avaliable with 15" wide supper turf tires if lawn mowing is to be a primary task.
The 1430 (and all models below) has a "pin-type" parking brake that operates only on the front wheels (I believe) like the "park" function of an automatic transmission in that the machine MUST be completely stopped before applying. This can be tricky if you are on a hill in the first place, and you may also have to apply opposite power to release it under the same circumstances.
So long as the engine and hydraulic systems are fully functional, you can slow down, stop, and reverse direction at will and very smoothly with these machines, it is under extreme conditions or catastrophic failure (such as burst hose) that a fail-safe type brake system can save your butt (and expensive machine).
The current PT price lists only show the 1845 and 1850 including a mower deck and with dual wheels/tires plus tilt seat, etc. They are really aiming these machines at the commercial/municipal market. They may be willing to sell a package more to your needs however.
Good Luck,
Rip
