I'm not sure which criteria you would like to use to name one broker as being 'better'. If you are looking for a regulated U.S broker, it's Interbank FX. Whereas North Finance is an off shore registered broker.
I have accounts with both as I've been with IBFX fo nearly two years and recently opened an account with NF. So far, so good. Each of these brokers offer different advantages and it depends what you are looking for.