Tinny,
I know what you're saying and it definitely has some truth. However, I found that if you had the altitude to play with, just drop down 1-3 thou' feet and the viz improved considerably. Trying to bash your way through the smoke haze close to the inversion layer was hard work.
From my experience the worst of the smoke haze was about 8,000' (inversion dependent) or so, therefore, a drop to 4 or 5,000' wasn't difficult nor too great a fuel penalty.
GPS's are useful for sure, but they can't solve all the problems.
Agreed re wet and bumpy stuff..
