The advantage of a corner placement for speakers is the corner and floor reinforce the bass, so you actually have more output in SPL terms. You can get too much, your ears will tell you this. If you have tall subwoofers, you get the effect the ceiling as well, so the bass SPL really goes up. Think of it as a horn subwoofer and you get the idea.
The same effect applies to the main speakers as well, but to a lesser degree due to the frequencies involved. But do try it, you might prefer it over other arrangements.
In my room, the right subwoofers are in a corner and the left channel subwoofers are on a flat wall. I am going to redo the room so that both subwoofers are in the corner. It also gives me more seating area in the far field of the speakers and less in the near field, which should be a good thing.