I just took delivery of a pair of 2.4s and have close to 40hrs on them. My initial impressions at the dealer above and in another dealer audition are still valid. Now that I have them in my system I'm even more impressed. The midrange is much better than I expected, and the way they fill my 16w x 20l x 9.5h room is very satisfying. I've had the 6s in my room for a long weekend (driven by Bryston 7B ST monos at the time). The 6s will throw a larger soundstage (more height, larger scale) and deliver deeper, more impactful bass. Musically I think the 2.4 is a better speaker. Its also considerably easier to drive. The 6 is not as coherent sounding, and has some hardness/brightness in the upper mids. The 2.4 is smoothly integrated from top to bottom, and still provides the resolution and venue information that Thiels are known for. I haven't spent enough time in front of the 3.6 to offer an opinion. I did own the 7.2s for a few years before downsizing and still think the 2.4 sounds more like a scaled down 7.2.
My system for reference: Resolution Audio Opus 21 run direct into a Plinius SA-102, interconnects and speaker cable are Pure Note Epsilon Reference, power cords TG Audio SLVR, BMI Shark, dedicated lines and Jena Outlets.
