Great post. 20K is what I have received under similar circumstances.
I am really stunned that you were able to have long conversations in the 787-9 -- how many bars of reception did you get? One big reason I hate the 787-8 is that it is a giant Faraday cage and I have 0-1 bar of cell phone signal on the ground. I wonder if Boeing was able to improve things for the 789 compared to the 788.