Speaker distance

Placing them on long wall away from the side walls is optimum IF you dont’ get cramped.  Speakers should be out from the wall and don’t sit too close to the back wall to get away from room boundry.

It’s very important to make sure your seating position is not in a null for poor bass response.

IME it’s very much about personal preferences.  Both can sound good but different.  Sitting in the nearfield takes a lot of the influences of the room out but gives yiu more of an upfront/closer to the stage perspective whereas sitting further away from the speakers allows room reflections to come into play more and can give more of a mid-hall perspective and sense of depth/open space.  I much prefer the latter, but you should really try it both ways if you’re not sure which perspective you prefer.  Hope this helps. 

@polkalover what are your room dimensions? 

Never could understand why a person listens with their chair up against the wall. I find an equilateral triangle in the middle of the room works well. 

In which part of the rectangular room the system will be located is pertinent. In an area facing a short wall in a rectangular room, I would first consider the most practical placement of the speakers within this area that minimizes boundary interactions with the front and side walls, as this is usually a limiting factor and ultimately determines ideal listening distance. One should try to get at least 1m of distance between the tweeter and those boundaries if possible. After determining speaker placement with respect to adjacent walls, measure the distance between the tweeters. Multiply that distance by 1.2 as per Jim Smith’s observations mentioned previously, and that should give the distance from tweeter-to-ear on each side. Toe the speakers in as necessary to give the most even response (REW helps tremendously). Mark this position with painter’s tape if further tweaking is desired, but this should get one close to an ideal position.