You should look better at the initial posts:
whimsycwdCTO
“When it comes to 3D printing, you can’t get fine results if you using high feedrate. We have been using 120mm/s to torture test the machine for months. But we recommend our users not to use speed beyond 100mm/s. It can cause lost steps using high feedrate in a long print.p”
So clearly the endurance tests have been done at 120 mm/s 