I used to trade on sfx but probably never again. UI is too complex. and for god's sake their spreads triple when there's volatility it's untradeable.

I use whaleclub.co now which has quite a great interface and importantly FIXED spreads although not many markets yet (I mostly trade BTC/USD and crude oil there). Also they have incredible support I can not say enough good things about them. jenny from @whaleclub if you're reading this, I love you.