Im writing this reveiw after more than 18 months of listening and comparing with multiple speakers. The speakers that i had compared was Sonus faber Concertino and Dynaudio Audience 52. I did not liked the Audience 52 the moment i started listening due to lack of details and also may be due to lack of amplification power and right electronics matching and sold it.
I liked Concertino close to Excite x12 but I had to keep it aside due to lack of warmness in low frequency, may be due to my amplification - but still i had retained it as my collection. Over all i preferred excite x12 with the available resources I had:

Some of the facts that i like about These little Dynaudio excite x12 are... they have GREAT resolution, soundstaging and imaging that no speaker in it's price range ought to have. Very impressive synergy and tone, guitars are easily distinguished and piano's have the appropriate balance. Piano is the most difficult instrument for the speaker to retain its origin and this dyn does it neatly.

Like other reviewers mentioned it has very sweet sounding / detailed Highs and Mid. Lows are incredible considering the size of its enclosure. Since im listening these speakers in Bedroom and not much accoustic treatment available, i had some hard time in placement of the speakers but finally i had decided to close the rear port with foam which came along with the speakers and it partially solved the room accoustic issues. More than any thing i had not felt the listening fatigue so far even after long duration. Still im waiting to ugrade my source in near future.

These speakers compliments with REL Strata III Sub, Audio lab 8000 P and 8000 C; Marantz CD 5001 player, Mogami Cables and Custom made Stand mount filled with Sand.

Simply a great speaker. Excellent highs and midrange -- clear and detailed, but smooth -- and fantastic bass for a small monitor. I bought them to replace the Quad 11L, a great speaker in its own right. The Quads were a good match for my previous electronics (Music Hall cd25.2 and a25.2), but, after changing to Naim (CD 5i and Nait 5i), I felt that I might do better in terms of speed, clarity, and low-end punch. The Dynaudios have been a revelation in those areas, and they're also superior low-volume performers. I worried that the Nait 5i might struggle to drive 4 ohm speakers, but comments suggesting that the X12s are in fact not a difficult load convinced me to give them a try. I am very glad I did. The Naim-Dynaudio combination is fantastic.

Quite good speakers considering their size. Highs are sweet without being harsh, Mids are open and clear. The bass is good considering the size of the cabinets, it is soo deep. They can even fill the bigger rooms, although they work bigger in smaller up to medium size rooms.