Left my car in "normal" mode, which is acting like "sport" is expected to, but without the soundaktor. Don't have to keep flitting modes to get the sporty response, unless i'm missing the soundaktor noise.
The biggest difference is the turbo assisted pick-up in power. In the normal (sport indicated on mine) mode the car seems to pick up strongly from 2100 revs, in sport (indicated normal on mine or after leaving sport and coming back to it), it picks up strongly from 1750 revs. The initial difference is noticeable, but above 2100 revs there is no difference between the 2 that I can discern. Me leaving it in "normal" (sport response for me) results in around a 5%/2mpg fuel penalty for me, but i'm enjoying the car so much with the DTUK box, I really don't care.
Adekil: When you leave yours in "normal" is it acting as you'd expect "normal" to, or does it seem a little livelier than "sport" without having to come out of sport and then back into it?
50mpg (indicated, likely 45/46 actual) on the way to work today with a heavy right foot.