I would think its just the difference in manufacturer, they're made in different factories so they are bound to feel different, my 28-90 seems smoother to operate for sure, but my 70-210 is well used, so hard for me to make a comparison, the shutter ring feels fine, but it is a more defined click, its going to depend on the size of the ball bearing & slot and the spring they use, I also have a Viv Tokina 75-205 and its has a similar feel and a Tokina 28-200 and its aperture ring is even clunkier. It may be because of the newness of the lens if it hasn't been used much, it may get better with use.
As for the zoom direction, I use a lot of different lenses so I'm not really conditioned to expect something to work in a certain way, I usually fumble about until I get the right ring turning in the right direction
cheers