RandyL wrote:

I can't seem to
visualize why Vx is not the best rate of climb.

I think what's confusing about it is that it's always presented in
terms of getting over obstacles at the end of the runway. You (as in
"everyone") always think of getting over those obstacles as quickly as
possible, which is why Vx seems "faster." (At least, that's the way it
seemed to me.)

So forget time for a second and think about it in terms of horizontal
distance: Vx will get you to a higher altitude over a shorter distance
than Vy. It's a steeper slope. And that's it. If you add time into the
equation, it'll take you longer to reach the same altitude along Vx
than Vy, but that's because you can go that much faster at Vy than at
Vx.

Hope that helps.

Marc