Bully Dog offers shift on the fly, but here's the thing... you don't really want shift on the fly.
It's not true on the fly tuning. Not on Bully Dog, and not on H&S...
Yes, the 6.4's and 6.7's hold up using H&S on the fly, but if you look at the tunes, you'll see why. All anybody is really changing is upper end duration. This keeps your transmission from freaking out.
You will NEVER see true on the fly tuning changes on these trucks. You'll never be able to go from a full on race tune to a safe tow tune with the touch of a button. You CERTAINLY won't be able to on a 6.0.
This is another great option in a land of disappearing hardware is all.