I'm sure I'm biased, but I always liked the π cornerhorns best. They just sound better. I've used them in a variety of room conditions, and the only rooms that I don't like with cornerhorns are those with raised hardwood floors. And I can't get those to sound good with any speaker, below 100Hz the floor becomes a resonator. As far as room confirgurations, I've had them in long rooms, thin rooms and those with odd shapes. The best are rooms with approximately 3:2 ratios and I usually like the speakers on the short wall. But other placements work very well too.Bass response is improved using this configuration, and since the mid/hi horns also have 90o dispersion, this makes all sound sources have the same pattern. It also reduces side wall reflections since the coverage angle is within the confines of room boundaries. It's like the walls become extensions of the flare instead of acting as reflectors. So the first reflections are those from opposing walls.
If you have the option of using corners, I strongly suggest you try this approach. I think you'll be very satisfied.