that's a matter of debate. there's nothing wrong with a closed system that's working well. In fact, it's better due to the higher temps you can run (higher temps are better for burning gas, but you can't go higher than the temp limit for the engine components). lots of guys tout that the open system cured their woes, but most would probably have fixed their woes when replacing the same components with new, but retaining the closed system. either or will work fine.
Is there any hissing or leaking coming from your pressure bottle? (the thing that looks like an overflow bottle)