I sent my F5 back to Geekbuying. Tracking says that they received it last Friday, and customer service says they are reviewing the unit. It’s frustrating that these platforms only have horrendous customer service – they purposely do not respond to whether I am going to get a replacement unit, even after repeating the question three times. I also stressed that the F5 was meant to be Christmas present and that I needed an answer quickly – they simply do not care.