Keep in mind that I have not been to the GR Melting Pot, but my in-laws did take us to one in Littleton, CO when we were out visiting. The concept started out as fun but got old. We did appetizers, dinner and dessert and were there over three hours. It just started to drag - although the food itself was tasty.
But the big problem I had were the prices. I was astounded to see how expensive everything was (and glad that we were not paying!)! It is tremendously expensive, and I don't even know what you're paying for! I mean, for all intents and purposes, the patron has to do all the work cooking his or her own food. All the kitchen staff has to do is cut things into small pieces. How hard is that? I simply don't think the cost is justified for what you get. I have friends who say you're paying for "the experience," but I don't buy it. The meal drags out too long, and you come out with your clothes smelling of oil and your wallet a LOT lighter.