Dear Fiona,
I think this problem may confuse many people, but it is simple. The only way can make you trust is testing and feedback from your clients after a long time. Sometimes, it is difficult to make choose, just like some like IBM, some like DELL, in laptop. We are confident on our product, every parameter we gave out is from testing and testing again. And sometime you must think of many factors, like cost, quality....
I think the reason you don't know how to deal with it is that you don't know much enough about products, I suggest you to find more information about it, thanks a lot for your attention on Hikvision.
Best day for you!