Haveing never heard the EP350, I cant comment.
As for the QS8s, I have mine mounted about 9.5 ft off the floor and about 5 ft higher and slightly behind my listening posistion.
All I can say is wow!
I love my QS8s, as well, all my friends love them.
From all indications, the QS8s are a VERY forgiving speaker when it comes to placement.
I listen to a lot of multi channel music, and although many say direct radiating speakers are better for that application, I find that they sound fantastic with it as well as movies.
