Just got my i3 from GearBest. It is REALLY bad. The center is 0.59mm high. Sent support an email and they pointed me to this page.
I loosened the set screws on the rods and they would not even rotate. Had to loosen the support screws to get the rods out. They are bent but not huge. Tried to put the rods back. The side with two bearings are miss aligned so much the rod will not go back. Will need to remove the bed and adjust bearing mount just to get back together. Sent an email to support with pics and asked for a replacement base that has been CHECKED. We shall see what they have to say. For a machine that should have been unboxed and start printing I'm not happy.