Hydrostat issues are very rare. Skidsteers, trackhoes, dozers, wheel loaders, manlifts, scissor lifts, trenchers, stump grinders, some cranes and forklifts. Hydro driven. See a trend here? Anything hydro is basically the same animal just sized differently. They all have tanks, pumps and drive motors and work on the same principal.
Since 2012 when I started researching tractors to purchase I have only seen 2 maybe 3 hydro issues on any of the tractor forums. Thats pretty good out of all the people on forums with Hydros.

I work daily on the machines listed above and we have some in the 8-11,000 hour range that have never had a hydro problem not counting hoses and o rings. We rarely see hydro issues that werent in some form or fashion caused by the user. Either lack of proper maintenance, continuing to run it low on fluid, hydro cooler not kept clear and it stopped up, or contaminated oil put in it.
Are they expensive to fix when broken? yes but the odds are they arent going to break under proper use and maintaining.
I used a 8n and a massey 135 before I bought my hydro. Those 2 would wear you slap out after a full days worth of stopping and reversing doing small food plots and trails. The hydro makes that same job much easier.

For most food plot, mini farms, homeowners, landscapers, average Joe the hydro is the ticket. Easier to use and much safer for the novice user.
For large Ag and ground working geared is better.