Wilf,
I was using the GM Syncomesh originally but the Tremec is just a beast to shift. Very sticky between 2-3 and 3-4. I went with BG Syncroshift and it improved a bit. However, once I threw away that Tremec stock shifter assembly and bought a Pro 5.0, all the problems just went away. The Pro 5.0 is a very short throw and smooth as silk.
I bought mine without the shifter arm and used my stock Cobra shifter arm.
http://www.pro-50.com/
Roscoe