Two considerations - effect on the speakers and effect on the components.
As noted, to "optimize" your sonics, you may want to avoid placing components in the middle between your speakers. This is more important if you include any video device (yes, even with 2-channel) because the screens are so reflective. But you must also realize that even a front-facing dynamic speaker transmits sound to the rear and the mid-point of the wall behind the speakers will be second only to corners for bass loading. This energy can induce vibrations which will not be beneficial to your electronics.
As a general rule, bass nodes build up at even fraction dimensions in a room; 1/2, 1/4, 1/6, etc. Bass waves are less for the odd dimension fractions; 1/3, 1/5, 1/7, etc. This is one reason for the unofficial "rule of thirds" for speaker placement.
Therefore I would consider experimenting with odd dimension placement for speakers (distance out from front and side walls), listening position (rear and side walls), and equipment (any wall, although the rack or stand is likely to be placed close to a wall; so for sonics and access I would place it out 12-18" if you have room).
Good luck.