CM Storm Spawn - Perfect Tracking
CM Storm Xornet - Not in thread (Is Xornet or Spawn sensor better?)
Roccat Savu - Not in thread
Razer Abyssus - Perfect Tracking
Zowie AM - Yet to be proven perfect
Zowie EC1/EC2 EvO - Not in thread

I've narrowed my mice down to these 6. What would you guys recommend for being the most comfortable? Also - is the Spawn or Xornet Sensor better?