I like the sounds best when the centerline between the woofer and the horn is on axis with the ear while seated. I have used the 4pi pro's and they where better for me when on stands or the least, angle back.
The theaters are larger and i've only heard them for short durations while on the floor. maybe this isnt an issue with those or the thermionic's which are very large.

I like the JBL 2226 a lot. this doesnt have gut wrenching lows but it does have clarity. This low distortion can bring music to another level aside from just playing it loud. Ounce I was satified with the new sounds I heard I began to search for some lower frequencies, and that meant bigger drivers to keep inline with the rest of the system.

Experiment. Sometimes you wont notice improvment untill you go backward and notice the loss. listen for a few days with familure material. make a change in speaker position and start listening again. There isnt a lot of science to trial and error. It will familurize yourself with the different affects speaker placemant will have that you cant get from a model or test gear though.

enjoy,

Bill