Looking for a better fluid for my transmission, I didn't want to pay $14/quart for Motul, nor did I want to pay more than that for Neo Synthetic. I had tried Valvoline 75w90 and did not like it at all. I decided to try GM Synchromesh, which is not cheap ($10/quart) and it was available to me the same day. The car shifts soooo much smoother and is much quieter. I highly recommend trying this stuff.
Oh and if you have not bled your clutch, I did that at the same time and it feels ten times better. This is all at 28k miles.