A very important aspect is that you are currently using electrostats, hence you will always desire an unboxed feel. I would suggest a pair of Manger Swings with a Zerobox subwoofer. The Swings do not play below 100Hz, hence a small room like yours will not affect it much. Below 100Hz just dial-in the amount of bass you require for your room, on the subwoofer. Simple, a very high end sound for small rooms.
What is the best speaker for a smallish room?
I currently have a wonderful EAR 890 power amp, a Klyne SK-6 pre-amp and a pair of Piquet modified Quads. It's a great combination but I'll probably need to relocate to a smaller room -- 11 x 15 or so. I am thinking about substituting the Quads with another great speaker. The quads are just great, although they move less air than I would like them to. I thought about a pair of Sonus Faber Extrema, but I believe they like large rooms. I am open to a bi-amplification solution. Thanks.