I must admit that I haven't read the replies completely. So here goes my stream of thought.
Ideally surround speakers need to be one foot above listening position. Not at ear level..So that rules out floor standers in my opinion. Thought one could theoretically use stands to elivate the floor standers.
If one goes for atmos, then all 5 or 7 speakers as per ones configuration need to be at ear level, so that over head atmos effects are more pronounced. Floor standers as surrounds work best here.
In my room with a 5.1.4 atmos setup, I would anyway prefer floor standers as surrounds if i had the room. Only because they are almost always more effecient than book shelf speakers.
Ideally surround speakers need to be one foot above listening position. Not at ear level..So that rules out floor standers in my opinion. Thought one could theoretically use stands to elivate the floor standers.
If one goes for atmos, then all 5 or 7 speakers as per ones configuration need to be at ear level, so that over head atmos effects are more pronounced. Floor standers as surrounds work best here.
In my room with a 5.1.4 atmos setup, I would anyway prefer floor standers as surrounds if i had the room. Only because they are almost always more effecient than book shelf speakers.