I switched to GM Syncromesh, it was a huge improvement. Plus with GM fluids they cannot deny warranty, well maybe they can with my mods....
Chevrolet Performance Synchromesh transmission fluid is designed for GM manual transmissions and is the recommended lubricant for all Tremec brand manual transmissions. It has been formulated with a partially synthetic base for excellent lubrication properties and does not break down after time. Chevrolet Performance Synchromesh transmission fluid can withstand high temperatures as well as cool, low temperatures