Which platform do we think is more reputable and have good track record of security? Does either of them have good liquidity?
Going with the typical way of determining about their liquidity, just look at the websites like coinmarketcap on this category.
So that's the list for dex and cex and if it's about the track of the record, you're able to get some ideas from the other members posted already on this thread. It's based on what they're using and what they've been with for a long time. And in terms of security, you need to remember that all of them can be targets and have vulnerability that will just be found out once an attack happens successfully.