IMO the LT will be about 1/3 slower Even though the LT will go 7 mph I dough you will be able to mow that fast? Why not look into air ride seat for you Zero turn? IMO you will really take hit on the Zero turn if you attempt to sell it. See what others have to say?

If you just drag the occasional cross tie you can simply drag it behind the X 500. But if you are planning to move a bunch of them, and would prefer not to create a logging trail effect from your efforts, you might want to explore the idea of using a two wheeled, pneumatic tired dolly for the rear end of the cross tie with a hitch plate/tongue plate on the front end to link to the tractor draw bar. Both the rear dolly and the hitch plate would be configured to fit the dimensional profile of the cross tie and securing each to the tie is done using one or two 8" C-clamps to secure them to the tie. Advantages of using a dolly and hitch plate are: Rolling pneumatic tires do little damage compared to simple dragging (skidding). With the dolly and hitch plate you can back up with the tie to facilitate tight turns or to back it into place near where it will reside permanently. This idea came to mind when I remembered a friend of mine who made a heavy duty version to transport up to 30 foot steel I-beams as a towed unit behind his 1-ton service truck.

I think you are on the right track. I'm also investigating zero turn mowers. I have a Cub Z with a 50" cutting deck, but want a zero turn with a deck that can mulch well. The Cub does not meet my mulching expectations. It's fine for side discharging. I've had good luck with Toro for mulching with my small walk-behind, but I'm skeptical of their zero-turn stamped decks. In fairness to them, I should go try one out. After researching this for the past few weeks, so far I like the JD Z225 or 45, Hustler Sport, and Bad Boy. I'm sure there are other good ones out there, but for the quality and money, these look appealing. To my knowledge, all of have welded decks and offer true mulching kits. I believe your chances for good mulching are improved with a 42" system, as compared to a much wider deck. I'm planning to stay with no wider than 48". If you are not mulching, I think many zero turns will do fine, regardless of the deck design. I do not have a clue as to which systems work well for bagging, but I'm not that interested in bagging. I'm a mulch addict. Hopefully, others will chime in with opinions about all of this. Hope it helps some.

In the end, you are the only one who can decide. While JD is a great, and expensive name, I suspect the one you are looking at for $2,600 is feeding on the JD name. In my case I would want to know how many blades each deck has. Many of the newer and cheaper 42" mower decks have gone to 2 staggered blades. I prefer 3 blades on a 42" deck myself. We have a stamped deck on our mower which is 18 years old and is still in good condition BUT you must not let wet grass accumulate under them, as many people do, or they will rust out. Most likely the JD had a B&S Intek engine on it while the Kawa is far superior. Walt Conner