In comfort mode there is always a delay (lag) when pressing the gas pedal especially when you are on lower rpms, happens in most cars and has to do mainly with emissions/consumption but also for durability. In sport/cupra mode it is almost unnoticeable but at the same time your revs are always kept higher affecting consumption and noise. The idle on comfort mode is on abt 900 rpm and on sport/cupra on abt 1100 rpm , this is the reason that on the sport/cupra mode you get a better response from the start as the revs are higher from idle.