You basically named the only two things. Linkage problem and fluid. Those two things are so simple you guys could have checked the linkage and replaced the fluid in the time it took you to post
I would defintely do that. If it still sucks, its probably the tranny. The funny thing is, having external problems that cause hard shifting (hydraulics, fork, linkages, etc) will end up causing bad synchros. So it may be too late anyway
