What's the mileage on the car? Has the manual transmission fluid ever been changed? How long have you owned it for(at what mileage did you receive the car and how many miles did you put on it since...what's the maintenance history of the transmission)?
I've done 2 fluid changes on my 2005 manual transmission(I wanna say the manual states do it every 60-70k miles), each time it was changed it was noticeably smoother. I used the legendary concoction of synchromesh(smoothness) and redline(racing full synthetic)... however, if I do it again any time soon I'd probably use the Motorcraft fluid(I don't recall the alpha-numeric code name for it off hand).