I can find the old, pre-Atmos, diagram I was referring to, but in the attached (current) diagram they have a recommended angle for FH speakers of 20-30 degrees. I seem to recall the old recommendation was 30 - 45 degrees which would make sense since there were no overheads involved back then. Regardless, looking at those CNET pics the FH's were on tall speaker stands, BARELY 3 ft. above the (quite tall) mains. And if they were sitting back any reasonable distance it would have been a pretty slim angle for sure.
Anyway, I have really tall ceilings so I am hoping for decent results. I'm already using an 18GBps HDMI switcher to route the UHD directly to my TV, so I am hoping this small surround improvement keeps me happy with my receiver another year or two...
Thanks again for the conversation - have a great night!