I've got a 5075e with loader, circa 2012 (i.e. pre-tier IV), so I can't comment on later models that are.
Knock on wood, but I've had no major issues.
The brakes work fine.
The 3 point hitch linkage is adjusted correctly so it does not go into relief when raised and melt the fuel tank.
Minor issues included: Tightening radiator hose clamps.
Changing the "made in Brazil air" out of the loader valve spring caps. The humid air in there actually condensed/froze in the winter. I would of added a weep hole, but wanted to reserve the right to sink the tractor up to the floor boards.