I traded futures with them years ago, I think they give a fair service. It is a regulated Spanish broker, sure you dont have problems to get your profit from them.
Now I trade with Oanda and Dukas and I did a search for best spread+comission broker and Ibroker was the best . Better than IC Markets, Activtrades, Dukas, Darwinex, Peperstone and FX Open They are new on forex so for now dont offer MT4 . They claim that offer institucional pricing and I think they say the truth.
You can try the demo and see yourself, I never have seen a platform with that amount of ticks so I think you are really trading against liquidity providers.
I dont know if they accept foreing customers, even the web is only in spanish.