My 2012 JD 1023E with ~800 hrs has been garaged >98% of the time.
At ~70 hrs white metal top link broke; cost to replace ~$150, ~$35 at Tractor Supply, with no problems over past 10 years. ~20 hrs later white metal clip holder for top link broke as well. Didn't bother checking replacement price
At ~250 hours gear box for mid mount mower blew. Replacement cost ~$350
At 375 hrs rear drag arm (which lifts mid mount mower) broke. Original part, inadequate in design, would have cost ~$40, but the JD engineering interns, realizing their error (one of many) developed a "new, improved" replacement costing > $450. Front drag linkage also started separating from mower deck, needing re-welding
At 440 hours ignition switch needed replacement (I also have a >80 yo Ford 9N with OEM ignition)! The 1023E has been sheltered as above. Ford 9N not so much
At 800 hrs,, front axle sprung a "leak", allegedly due to bad wheel bearing and seal. I was told the wheel bearing failed due to heavy loads in front end loader. The FEL maxes out at ~ 500# load; it's impossible to believe there is not a wheel bearing somewhere out there that can't handle a 500# load! (JD claims this is a tractor, I think it is a cost-cutting prototype. The Ford 9n still has OEM wheel bearings)
Also at 800 hours the replacement gear box for the midmount mower developed a leaking seal requiring replacement, and the mower "quick mount" (oxymoron) carrier and bearing needed replacement
The word on the street and internet is that JD started outsourcing parts to off-shore (read "chinese") suppliers around1999-2000
If you need a tractor, get an orange one.
The JD marketing lizards and engineering interns have ruined this brand