Our living room is about 21' x 14' (8ft ceiling) and my R3s 'fire' across the width of the room. Allowing for depth of speaker + distance from the wall + position of chairs the listening distance is about 8.5'.
There are also large, solid wood, book cabinets to either side (both around 3 feet distant from each speaker) one against a reflective wall and one forming a bit of a room 'divider'. Both are full of books/boxes, DVDs etc.
Essentially this makes this end of the room (with the hi-fi) a 12' x 14' space with the speakers seperated by 6' distance.
I have the R3s pulled forward a bit so their fronts are clear of the TV/Humax/Marantz etc. I used to have the side mounted bass speakers firing inwards but now they fire out (into the bookshelves 3 feet away from from each).
Solid floors (with thick Dunlop underlay and carpet) and solid brick walls on all sides (Edwardian house).
I use the carpet piercing spikes.
Although I tend to listen at 'moderate' levels normally, I have turned the wick up on a few occasions and the R3s have no problems filling the space.
Mind you, my idea of 'turning the wick up' might not be the same as yours. Some like the sound at 'ASBO' levels! I don't think the RS3s would be for you if that were the case.
What size is your room? Is it very reflective?