In general, I believe it takes inherently more power to get "kick" from omnis equivalent to what you might get with similar efficiency directional speakers aimed at your listening position. That is because with imnis, the sonic energy is emmitted in all directions whereas with more directional designs it is all essentially aimed at you.
Due to room constraints (12X12 with some large furniture and a TV in the room)I've had my 100S3s in a rather unique more wide and nearfield configuration for the last few months that I have found works well, yet is radically different from the typical setup and even how I have my 5s setup in the larger room.
My listening position is a couch on the rear wall. My electronics are on furniture occupying most of the left wall. The TV is in the front right corner, and there is a sizable computer desk center on the front wall.
The left speaker sits about 2/3 of the way from the left side of the couch to the rear wall. The right speaker sits about halfway between rear and front wall (about 2 feet further out from the rear wall than the left) and only about a foot from the right wall. Everything is tuned in quite well with more than adequate bass, proper top to bottom balance, detailed imaging and a room size sound stage that can almost immerse the listener in the music.
Its a totally different presentation however than in teh larger rooms with the 5s which are both equidistant from teh rear wall, about 5 feet apart, and where I normally listen a good 6-8 feet or more back from teh speaks. Occasionally, I listen from a chair that is about 2 feet in front of the speakers and about a foot to the outside of the left speaker. There, the soundstage is again more near field in nature and the image fills in nice and coherently with a slight shift in overall location to the right....the magic of omnis!