After 4 years of use, I have had zero problems with my mower. I replaced the blades once, did the initial oil change and completed one maintenance cycle (grease, oil change, filters, etc.)
The only problem has been a slight steering drift I easily adjusted for, and a flat tire, which was my own fault.
This machine cut my grass cutting time in half and I can now mow my entire 4.5 acres, if I want. Often I do less and bush-hog the over growth.
I do grease the jack stands each season, sometimes twice.