I have worked with several people refining systems with Thiel speakers. When I see someone looking at new speakers it is because they are looking for something that doesn't seem to be in their system currently. The system needs to be refined to put the Thiels in a better performance range first or it is unlikely that a speaker change will get you what you are looking for. The first improvement comes from dead neutral wire which smooths a system out to a huge degree while revealing even more detail and ambiance, the tonal balance improves and takes on a better bass to mid to treble perspective as well. The two best for this are the most affordable as they outperform the likes of Valhalla and other flagship high end cable, they are Audience Au24 and JPS Labs SuperConductor 2. After that a Belles amp adds another degree of smoothness and involving musicality, they are the better than most insanely priced amps. For less than a speaker change these upgrades will give you far better improvements, and then you are ready to really compare speakers, although at this point you may be a very happy camper. The tendency will be to not believe cheaper cable could possibly outperform what you have if you spent major money, trust me here, the amount spent doesn't mean diddly. The cable can be tried with a money back guarantee so there is no loss if it doesn't work. Same with the amp. Touch bases and let me know what you are currently using and I'll point out your weak links that will make real differences.
Regards,
Keith
Holy Grail Audio