Already Rank 33 with my current chocobo and I can safely say I have not once considered really pumping stamina/endurance/cunning thanks to current track layouts. Everything has gone into speed/acceleration. I did some stam/end early on for a minor boost but since about rank 15~20 I haven't needed to raise them anymore.

The current tracks are pretty much just "you either go fast or you get screwed". Weather at least plays some factor in that it seems to slow you down/increase stamina consumption if you're lathered, but its really not a major factor (unless bad weather persists for the WHOLE race).

And what does cunning even do- I never saw it explained.

Edit: All in all, its a new system. I'm sure Heavensward will bring some changes. Right now it seems like they wanted to get a good framework down. I think its in a good spot to be expanded on.