I don't really understand how one can begin to craft an argument saying it isn't. When something falls under a larger field of study and is accepted as a relevant thing, how can you say it isn't significant to what it's filed under? Every instance isn't going to go down in history as a major event, but the practice overall is meaningful.
What is philosophy but a grand experiment of the human condition? One does not need to quite Aristotle or Plato to follow a philosophy. One creates his/her own philosophy of the world. It is the fundamental aspect of humanity to think for one's self. Experimental philosophy challenges us to form our own opinion on the matter at hand. My philosophy on life will no doubt clash with others. It is what makes us human and to forever question and experiment.
I come up with my own theories and philosophies all the time. In fact, most philosophy is experimental until it has been completely proven over the years and widely accepted, which in most cases doesn't happen. Philosophy can be beneficial even if it just shows you how odd some people's perspectives are and how having an open mind can allow you to see things from a different point of view, even if you don't live by those things, or believe them. Sometimes having beliefs that you felt like you invented can really boost your mood and social life.
I don't think that we can really ever hope to one day make the claim that experimental philosophy is philosophically different from any other forms of philosophy. Try saying that phrase five times fast! It is certainly different in a way, but to call it significant would be going too far.