I have tried many speaker cables with both my 3.6 and CS6 and always seem to come back to Straightwire Maestro II. I do not believe you need a cost no object cable for Thiels unless you have similar equipment.
I have tried several $$ speaker cables including:
Alpha Core Goertz M2 and M3 - nice balance overal, M2 better - RC links a hassle
Kimber 3035 - dull sounding, good bass however, silver/copper mix not ideal
8TC - solid, neutral, puts out what is put in, will always have a pair on hand
StraightwireVirtuoso - disappointing since the Maestro is so good, grainy,
Tara Labs The One - solid core not for me or Thiels IMO
MIT Oracle V4 - aggressive top end, great bass
Magnum M2 - good but moved up the line to V4
750 SG - a classic in my HT system. Warm full bodied holographic. slight bloat.
Purist Audio Proteus - gave up too soon on these. Used them with another speaker
Nirvana SL - nice, but lost in a cable co shootout with SW Maestro II
AP oval 9...just to name a few. I have what is called a cable fettish!
After all that SW Maestro II is in my system today. I have PAD Venustas IC's upstream. I believe you can get more out of experimentation with interconnects than speaker cables with Thiels.
Of course this is my perspective in my system YMMV. Only way to know is to try IMHO.