Honda MTF in my S2000 every 30k miles. It had GM Synchromesh Friction Modified MTF for about 20k early in its life from around 10k to 30k, I didn't like it after 15k so I changed to Honda.
Most Redline products are basically shear proof. With my Accord, shifting is less smooth in the winter. Where the Civic with the Honda MTF feels the same all year round. Could just be the Honda 6-speed transmission, or the fluid.
Amsoil Syncromesh is also very good. IDK if it has the same shear resistance as Redline though. I do know that Signature Series basestock is NOT used for the Syncromesh.
So personally, if your gonna spend $15/qt, i would get the Redline. But if you dont beat on the car, and just daily drive it... save your money and just get the Honda MTF.