I too thought it is Eco mode. A slight delay before pulling off.
I have 800 on the clock and started to play with sports mode. Not noticed this in S mode.
Another poster mentioned there maybe a gearbox software update to tackle this.
I haven't checked with my dealer yet as I'm going away for a week but will check when I get back.
My car is better since its software update but there is still a lag. Driving in Manual mode shows my cars true potential and it is much more urgent (and enjoyable). Oh for a proper manual box - I'd trade in an instant!
I think the 'E' mode softens and smooths the drive but you loose the punch much like a torque converter saps the power in a full automatic.