How much room is needed for Snell AIII ?

I have a room that is 18'x15' with a concerete floor and 8' ceiling. I do not have any restrictions on how I can place the speakers in this room. I want to hear from current and former owners of Snell AIII speakers if they think that my room is large enough to accomodate these speakers, and have them perform well.

I owned a pair of AIIIi's for 18 years, set up in a room 26 x 15. Ideally, they need to be set up at least 18" from the back wall and about 7' apart (inside edge). I would say your room is large enough. Place them as above on the shorter wall, toed in to be equidistance from your main listening position in the center of the room. I highly recommend acoustic treatment on the back wall.
Put them on the long way 3 feet from back wall and 2 1/2 feet from side walls, toe in exactly 3 1/2" each. Deaden the walls directly behind the speakers centered twice the L X W of the speakers. Tube traps in front corners. Have sitting area centered exactly 9 feet from the speakers. If using a sub put on right or left side firing across soundstage with sub pulled out 1 foot from wall but 6" in front of leading edge of speaker. If tile or wooden floors put heavy throw rugs on floor. Usually I charge $100 an hour for my services. They are free today/ If you follow this you will be rewarded with excellent sound
Thanks to all, especially you Verneal, for your very specific and helpful recommendations. From what I had read in the past, I didn't think that they needed a very large room, and you all seem to confirm that.