User based app; checking if the platform has a user friendly interface is a must because this makes the day to day transaction processes more easier and efficient
Security standards; I think this is the major checks before investing with any CEX platform as a user. Usually it’s better to check out for the hack history and prior security bridges.
Out of these two options, I must check about liquidity. If the exchange doesn't have much liquidity, then I don't bother to trade there. Security is one of the key points we need to double-check before choosing an exchange. Hacking might happen even if the security is high, but the exchange should be capable of compensating for the lost funds from the hacking. Otherwise it's very risky to use a centralised exchange.
I often choose CEX from the top. Before, I had used Binance, but after an issue with Binance, I am now using Bybit. It looks like a user-friendly interface to me, though using Binance was pretty easy for me. Also transaction processing time is pretty good on Bybit. However, it doesn't matter much what exchange you use; it really depends on your experience. But always keep in mind, don't store any big amount of funds in a centralised exchange to avoid harassment later.