The brakes on our TT had grease in them in under 1 year and had to be totally rebuilt under warranty. Never did any hard braking and didn't notice anything but were fortunate not to have to ever do an emergency hard stop. This is actually the 2nd TT we've had this happen to in under 1 year and 2 out of 3 TTs we've owned and two different axle brands. Not encouraging statistics. How many are out there with the same issue and don't know?
How many inspect their brakes annually, know what condition the wiring is in, test periodically and know if all 4 brakes are working properly when they head out on each trip? Owners don't trust their China bomb tires but they don't think twice about brake quality and condition?
Given the quality problems TTs are known for and lack of regular inspection and maintenance, I think anyone who relies on their TT braking to be fully functionally when they need it the most could be in for a rude awakening one day, especially if driving at high speeds. And that's not including those who tow over weight ratings.