cat, I've built about 10 or so for myself, family or friends and all are still operational without problems. The only difficulty was the first kit came with a faulty controller which was replaced and six plus years later it's still running. My family had a picnic at a large local park on Sunday and many individuals were riding around on "cheap" e-bikes, but I didn't see any OEM (big manufacturers) there. None had a problem. Of course, real data doesn't impress individuals who are bike shop owners or workers since their economic future is at risk, so they just throw some anecdotal quotes around.