There isn't a 3 second delay, I tried both settings and couldn't tell any difference.
Having said that I cannot really tell any difference between Normal, eco and Sport modes either except for soundaktor noise.
I may leave the soundaktor as it is, in individual I have basically got the same settings as in Sport, but soundaktor set to eco, so I cannot hear it. If I want engine noise I can always switch to sport.
On the better half's car (Alfa Giulietta) there is a huge difference between the driving modes. Not so on the Golf.