Chosing between lawn tractor and zero turn

I got some great advice on here a few years back, so time to come back for more help. My property is 3.5 acres total. Removing the house, driveway, etc..., I have about 3 acres of mowable properly. 90% of that is flat, though a bit bumpy in spots, open field. Very few trees or bushes to navigate around. The front of my property has a relatively steep downhill that leads to the road.

I currently have a Toro Z4200 zero turn. Got it end of season 2009, it was a floor model from Home Depot at the time. It has the Kohler 19hp engine. It's been a good mower. Does my lawn in about 2 hours. I can do the hill with it if I'm slow and careful. Well, today the engine went boom. It's got a nice size crack in the front of the block. From what I've since read, it's apparently a common issue on single cylinder Kohlers. Anyway, now I'm at a crossroads on what to do and wanted input. Don't have the budget for a high end garden tractor or industrial zero turn.

From what I could see, the Kohler motor is $925 just for the engine, plus the labor to replace it. So I'm guessing it's a $1500 total repair when all is said and done? Or I've seen lawn tractors like the Husqvarna YTH24K48, which would be in budget. It's a 24hp Kohler Vtwin (more reliable than single cylinder?) and 48" deck vs my current 42" deck.

I like my current Toro, but would the Husqvarna be better suited to what I need? Stronger motor, bigger deck? I don't have experience with them. Are they rugged enough to mow 3 acres, and can they do it fast? In the end, would you fix the Toro or replace it? I've always kept good care of it, but assume at 5 years old it's going to have other things needing replacing soon just due to normal wear/tear. So I'm not sure if I'm better off with a new lawn tractor under a warranty or fixing the zero turn. I know there's some personal preference involved, but would like some objective input. Thanks for any suggestions you may have.