Being the odd duck (I realize this is a Kubota forum but), I have a Cub Cadet 60": tank with a 27 horse Kowalski and twin Hydro Gear IZT transmissions and it's at least 10 years old and mows 7 acres all the time. Been bullet proof.
I didn't want to spend the jack for an orange zero turn and I have to say, other than consumable parts and engine oil and IZT oil, I have had 0 issues. Nice thing about the Hydro Gear pumps is, they take the same 15-40 motor oil the Kowalski does, no UDT or SUDT and if one goes bad, you can replace that unit instead of the entire transmission.
Replace the blades every spring and grease it regularly (has a service reminder built into the hour meter.)
Finally, replacement parts like spindles and pulleys are pretty generic so you can buy them at any online mower parts place, not from a Kubota dealer.
Had to replace a spindle last year (my fault) and the complete spindle, bearings and all was 34 bucks. I bet the similar Kubota part would be at least 100 bucks. Blades are generic too. I run Oregon high lift blades, 3 blades are 54 bucks new, delivered. Wonder what Kubota blades cost...lol
I see Kubota uses Kowalski motors for their non diesel mowers too. Good motor. My hour meter shows 800 hours and other than oil changes and 1 air filter and 1 valve adjustment (that I did myself) the motor runs just fine. Original plugs too.
Was a very good investment for me and thousands less that an Orange or green 0 turn.
Finally, it's festooned with grease fittings. Something I look for. Everything from the front wheel spindles and wheels to the deck lift mechanism is greaseable.
My 2 cents. I hate mowing lawns anyway. I should let the cattle graze on the lawn and call it good.