Well, Bitfinex is a great exchange, but quite old right now. Reliable, but not innovative. I prefer pretty new exchanges with huge potential to become powerful. Check out for example CoinDeal this is exactly what I'm talking about. It's safe and progressive in the same time. Recently, they have launched their new mobile app so you can check it.
Speaking from the perspective of a regular exchange user, Bitfinex is a good option. At the moment, I am pleased with the functionality that the exchange represents. Moreover, most other users speak well of Bitfinex. The link confirms this - https://revain.org/exchanges/bitfinex. Of course, there is a small fraction that writes negative reviews. I cann't say anything about this, since in my case there were no negative incidents with this exchange.