Hi Grimis,
This can be very room-specific. In fact, it can be everything-else-in-the-room-specific. As said bass will be augmented by placing loudspeakers in corners. But rooms have standing waves, and yours is large (how large?) Standing waves can be serious and cancel bass augmentation effects of corner placement depending on where you are. Also for stereo image you can have the loudspeakers too far apart and have the well-known "hole-in-the-middle". You will need to tests this ... and your findings will probably change with people in the room!
If your set-up is only for entertaining then I would think it does not greatly matter. Folks will wander all over the place; there will be better and poorer positions, and frankly I wonder if they will notice. But if you will on occasion also like to (seriously) listen on your own, forget about the people and set up the loudspeakers for that. As said above regarding people .......
[I have never found corner positions good for stereo imaging. It has to do with the adjacent walls' reflection effect especially at high frequencies, sort of "smearing" the source and generating vagueness - a topic on its own.]
