Originally Posted by civicized

You can feel the difference. A trans that shifts smoothly without grinding, "feels" better than one that requires more force and grinding to swap gears.
A new set of honda syncros on a freshly rebuilt trans feels better and shifts with less force with syncomesh fluid than standard motor oil. There is no question about it in my experience. I understand it helps shifting with badly worn syncros as well, though obviously it doesn't "heal" them.