Entirely depends on the quality. Every seller is different, but one thing that's safe to assume about them all is that you'll get little to no customer support on it. Some people get thousands of kilometers on cheap bikes and others are left with a broken bike and no help. Personally I'd get one if I hadn't already started building my own, but that's just because I don't care about customer support and I like tinkering with stuff. Careful with the batteries though, ideally charge them outside and/or far away from anything flammable. It's unlikely, but some cheap batteries can explode due to low quality nickel strip, bad spot welds, or absolute garbage cells. I ordered my conversion kit off alibaba and it works great, so I had a good experience. I'm ordering my battery custom from Amorge on Alibaba as well. Alibaba is a trustworthy site, just make sure you find good sellers.