Well, in an emission scenario I would argue gotoh would have been superior to someone using simple nen bullets. He was enhancing the properties of the coins (an object which for some reason has some significance to him) and he had a limited number of them. Ultimately this is the exact kind of scenario where someone gets a boost for determination and whatnot. The issue ultimately was not that gotoh's ability sucked, the issue was that hisoka is insanely strong on a bad day. Heck, hisoka should be by all intents and purposes even stronger than most zodiacs.
As for gon's nen, well, the issue is exclusively that he is still young. His rock being slow charging, his slow emission or whatever flaw his sword has can all be fix with time. Eventually his paper will end up being just about as good as razor's nen ball, his rock about as good as uvogin's big bang punch and his sword about as good as... a nen sword (LOL?). I don't think we will actually see gon using a fully developed hatsu nor how it would work under such scenario, it would take too long.
As for gon's nen, well, the issue is exclusively that he is still young. His rock being slow charging, his slow emission or whatever flaw his sword has can all be fix with time. Eventually his paper will end up being just about as good as razor's nen ball, his rock about as good as uvogin's big bang punch and his sword about as good as... a nen sword (LOL?). I don't think we will actually see gon using a fully developed hatsu nor how it would work under such scenario, it would take too long.