First things first, HFM is one of the top-tier brokers in the world, and you should have no worries about its reliability since millions of traders worldwide trust and trade on this platform. Aside from its reliability, the main factor for their success is the trading conditions they offer - a great range of tradable instruments, pretty high leverage, no commissions, tight spreads, lightning-fast execution and so on. If I point out some areas they need to improve, it would be the account types. While the Pro account offers some really tight spreads, I think including a Raw spreads account wouldn't hurt anyone :)