I just wanted to come in here and let everyone know that BITMAIN customer service has certainly stepped up their game (or maybe I was just the one with the problem to begin with). Of the 3 S4's I purchased, only one has ever given me troubles, and in the past I was probably a little too emotional rather than rational with them. I recently had a minor issue with my S4 and the BITMAIN North American team is taking care of me! Have been very impressed with their communication and I can tell that BITMAIN customer service sincerely does care about their customers and are willing to stand by their products. Keep up the good work, BITMAIN!