agreed John
Dyno's still offer things a racepak cannot but a Racepak ( data gathering) offers us many things a dyno just cannot.
I do like the engine dyno for several reasons- one of course is that if we have any major issues we don't have to pull an engine.
The second for me is the repeatability that allows for testing/experimenting and that it doesn't put wear on the car.
But as soon as i can gather more data- I doubt i will ever use a chassis dyno again.
You have your chassis dyno every time you make a pass and with far more "real world" data than a chassis dyno can give.

If a brand new build car build and it was high hp, I would likely still hit a chassis dyno for a few pulls but, thats about the only reason i can think of if i had a Racepak.