I just replaced the bushings in my shifter because I was getting some weird shifts into 1st and second and reverse. I took it all apart, replaced the bushings, and added MOS2 grease. That made it feel so smooth it was like it was floating on air. The shifter was also very springy and returned to the center from both right and left with a sharp "boing."
However, after I put the cables back in and reinstalled the box into the car, the shifter is slightly slow to come back from the right, and barely comes back from the left at all by itself. It still shifts fine, I just have to maneuver the shifter without assistance of a spring.
I know I assembled the shifter correctly because upon discovering this I took it back out, disassembled it, cleaned it, reassembled it, greased it, tested the movement, reinstalled it, and tested it again only to find the same results.
So, bad cables? Bad shift tower?