I've owned 3 pairs of Vandersteens (1B, 2C and 2Ce Sig II). Also owned Electro-Voice, Genesis, Boston Acoustic, Acoustat, Klipsch, Mission, Monitor Audio, Pioneer and B&W.
Just sold the 2Ce Sigs. Still have the Pioneers (living room), the Monitor Audios (bedroom), and recently purchased the B&W 803 D3 for the dedicated listening room.
For me, the 803s do everything I like a speaker to do. They were the store demo models and I got them for close to your budget ($11K).
Compared to the Sig IIs, the 803s are more dynamic, have more bass, have cleaner bass, mids, and highs, image better, play louder, and just flat out sound better. As they should considering they cost $20k new vs $3.6K for the current Sig III. That's how I hear them. I LOVE how they sound. Just my 2c. YMMV