I think it depends on what you consider "economy" mode...
I notice it will up-shift on its own to 5th gear even when going about 35mph in D mode (since we don't have an OD button on the stick).
Also - if you read your owner's manual, you should NOT use regular gas in the V6 - due to the high compression of our engines, 91 oct min is required.
I didn't realize this either when I first got my car, but did notice better/smoother performance with the fuel in it.
To clarify the hesitation issue - it's not as apparent from a dead stop or at speeds over about 45-50mph.