CEX exchanges usually have much more volume when it comes to trading volume compared to DEX, but which one you will treat and consider better is based on what you want to use it for. With DEX, you still have control over your coins until you authorise it for sales and conversion, which is different from CEX, as you need to send directly to the CEX depositor address and wait for confirmation before you can do anything with it. Their fee level also depends on which one you are making use of.