Tired of the cheap 80cent bearings from a local electronics shop, I splurged for this bearing. When I first put it on the rod to move it up and down, the bearing felt sticky, like the balls were binding inside. Thinking that maybe the bearing needs a bit of breaking in, I pressed the sides of the bearing against the shaft to ensure the balls had contact with the rod, and slid it around. I could feel everything loosen up, and now it slides like glass.
I spoke with Jason from 3DPrintingCanada, and he confirmed the bearings can sometimes need breaking in and told me how to check if the bearing is good or bad. He was really friendly, happy he could help, and really knowledgeable. I'm really happy with my purchase and will definitely come back when I inevitably need more parts! Thanks Jason!