My Def 2s are 11' apart, toed in pretty severely, and placed close to the long wall of a 14.5' x 22' x 18' high living room whose other long wall opens up to the rest of the house. The speakers are essentially at one end of a 22 x 45 x 18 volume that is broken up by a fireplace, partial internal walls, etc, but that is otherwise hard-surfaced (solid plaster on stone walls with hardwood on concrete floors) and untreated. They are driven by either an EAR 859 or a Yamamoto A-08s SET amplifier (I cannot make up my mind which sounds better) and an EAR Acute CDP (currently in the shop, but that is another story).
With the caveat that I have heard very few speakers in my house for comparison. . . .
Compared to the Def 1.5s . . . they have more presence; nearfield listening is improved and better integrated; there is a good soundstage regardless of where I stand or sit in my living room - even to the far right or left of both speakers; there is absolutely no listening fatigue; there is more high-frequency sparkle, but treble is still smoothe; bass is tighter, cleaner, and more integrated; attack is improved with better impact; set-up is much less fussy; and tone is huge (although a bit darkish with the Yamamoto amplifier) and IMHO even more dynamic and life-like especially on the proper recordings. Perhaps not the final word in microdynamics and microdetail, but I really do not pay a lot of attention to such things. And perhaps not the deepest soundstage; but, then, the Def 2s are within 4 from the back wall. And when they play, the entire house fills with music - glorious.
I opted for gloss black with aluminum rims; matte black was not available when I ordered them. However, I like how the gloss black anchors one extreme end of the visual spectrum while my white walls anchor the other - the visual analogue of great dynamic range.
