At 1st I also confuse, then I read again and check it sequence where it is from Good to Best Available to Better. So I am pretty sure Better is the best and during test out it give me high quality playback from all time. Also if I choose Better, my connection is nearly pull over all by Apple TV 4K because my browsing speed in PC that connect to same network is kind of slow.
By sequence it is from Good to Best Available to Better which means the least is Good, the best is Better. The Best Available is in the middle. I can't get sharp image from time to time if I use Best Available but always sharp when using Better. By the way my connection speed is in between 45Mbps to 65Mbps
- Good - Watch videos in SD and use less of your data (mentioned SD and use less data, this setting priority in less data usage)
- Best Available - Watch videos in the best quality available based on your TV and connection (mentioned in between quality without indicate it is SD or HD and this fall in between and connection which means it is tolerant in between quality and connection)
- Better - Watch videos in HD an use more of your data (mentioned HD and use more data means it priority in quality and use as most as need the connection data)