On the one year and a half i've been using Bitfinex, i have to admit that they improved on most of what was wrong in the past. Following their 2016 Hack, they took security to a whole new level, to the point where it's almost impossible for anyone to steal your funds if you have apropriate settings on your account. Their customer support team really stepped up their game, as tickets are now almost instantly responded and dealt with. The only thing that in my perspective is still in need of a change is the 10K USD Verification "fee", and the time it takes to get verified. The value is a bit too steep for most people, and as such scares potential customers away. In all other aspects, Bitfinex outshadows all other exchanges given some of their unique features like advanced order types and margin trading, and their sheer volume and liquidity. If you have the 10K, definitively give Bitfinex a try, you won't want to use any other exchange.