As a cryptocurrency user, in terms of choosing an exchange of course we have never separated from some of what we want, for example convenience, security, quality, liquidity and low fees imposed on users. Besides that, the available coin pairs are also supporting factors which can be considered very important, and this thing can give customers many choices for the coins they will buy. So, that's some important points which I think are worthy of being taken into consideration in choosing a good exchange.
I think something like security should not even be a comparison because security is NON-NEGOTIABLE. You must have it, which is why I am never comfortable with having no private keys. However strong the exchange says their security is,,, they always fail eventually either through carelessness or technological inferiority when hackers strike.
What distinguishes exchanges are convenience, friendliness and support efficiency.