I just took delivery of my 2015 Vantage V12S. The car is awesome. My neighbors, one of which has a Lamborghini Hurican and the other with a Porsche GT3 were also very impressed. Though,we noticed that the exhaust note doesn't change much with the sport mode on. Is this the case with other cars or do I need to have the dealer check it out?

 

Interesting observation. I've had mine for coming up on a year, and had an independent adjustment of the valve (key fob remote) added on delivery. I had the same problem noticing a difference as you at any revs, and thought maybe the install was the problem, although I was assured the fob was indeed operating the valve. Sounds from your description like the maybe issue is intrinsic to the exhaust design on the S. Pressing the sport button on my old 'regular' V12V made a noticeable difference in exhaust note at lower rpm.