I got a month's trial of Prime Video and have it installed on my Tab S (UK version) and Shield TV (US version via vpn as its not officially available on Shield). But there doesn't appear to be multichannel sound available. In fact, there aren't any audio or video settings at all. I watched a full movie on Saturday night and it didn't even hit 1080p, and thats on a VM 200mbps connection. Is there something I'm missing?