Proper positioning of surround speakers should be above seating height. This is how almost ALL movie soundtrack's surround information is mastered. Next time you go to the theater, note how high the surrounds are on the wall compared to the seating positions. Now, if your surround speakers were small enough in size, having them closer to you would probably be an advantage. My surrounds were designed for medium sized cinema venue, and I have 4 of them in a room that's barely 12 feet across. I love feeling emerged in the sound field, so small surround speakers don't cut it for me.
Also, Klipsch's Pro Cinema line is usually less expensive than their high end commercial products. However, they do have a more "industrial" look to them. (IE Metal grates instead of speaker cloth for covers)
So I'm guessing the reason why you don't have the "muddled sound", is because you ran some sort of room correction software that came with your receiver. This is very common. The software detects room issues and then tries to process them out of the raw sound. This is VERY important with Atmos because Atmos speakers that are pointed up run into crazy variables. Style of ceiling and height are variables which need to be calculated and then processed into the sound. When you fire from a speaker downwards, the processor assumes your speaker is correctly placed, and doesn't process the sound as much.
I'm a believer in the theory that there should be NO extra processing anywhere the sound path, as it reduces quality. Instead, you should fix your listening space. I'm a stickler for quality. However, I built a system that is so sensitive, that I can hear the audio compression in ANY type of streaming content. I have to use a Bluray to get the best quality out of my system, and even then if the source material wasn't mastered well, I can hear the errors.
