Told to drive in 'Power' mode?

[Parkway]

Firstly, sorry if this is in the wrong section.

Anyway, I just got my automatic serviced and when I picked the car up the guy brought up the fact that I drive in 'Economy' mode and that I shouldn't. I was a little confused because I always thought power mode was only really used for towing (as stated in the manual) rather than city driving.

Now I'm not too sure if I should take his word for it, although he seemed quite professional and has probably been in the business a while. He also told me a whole heap on why it's beneficial, rah rah rah and that he spoke with the chief of Borg Warner but I'm still not convinced.

Do tell...