How advantageous is it to have presented a poster at an international conference? I am trying to figure out how important it is for a grad student to present their research at a conference.
Let's assume the paper with the research is definitely going to be published. 


Does it look better to a potential postdoctoral advisor if the work
was also presented at a top international conference? Could it be the
thing that gives one candidate the edge over another?
Is networking at a conference much more effective if you have a
poster to refer people to?
Is there any point in going to a conference without a poster?


To give you some more background, why I am asking is because my supervisor has said that I can attend a conference but they don't want me to present a poster (my data is too preliminary). However, if it was really good for my career, I would be willing to challenge them on this point. But first I really need to weigh up if the advantages of presenting outweigh the chance of annoying my supervisor. My other option is to not attend the conference at all, and instead delay going to one until I have solid results to present, but I'm afraid of missing out on this opportunity.
It's probably best to listen to your supervisor, especially if they have seen your data. If they have not, show him/her your work and explain to them why you believe this conference would benefit from you presenting. That way you have greater clarity regarding why they disagree, and you frame it as the conference benefiting from your contribution rather than you simply gaining a reputation advantage by presenting premature data.