If I am choosing the exchange to use I want some which keeps their promises, have quick and nice customer center, have a high volume (not to be stucked) never been hacked and last but not least is user friendly. It is always good to check how famous and popular the exchange is. There are not so many exchanges that is why the Bitfinex deserves attention because it fits to all of the above perfectly. From my personal experience I have been always treated well. The have enough features which you can use alongside spot exchange. The have also OTC opportunity. For your convenience you can use app or web exchange. It can be as a disadvantage that it is CeFi but for me it is the prefered option. Overall great exchange to use without worry as it is fully developed exchange.