My Exige used to hold back now and then when revving. Also, when driving it felt a little “nervous”, like not all power was available.
I brought it to the dealer 3 times, and the third time they got it resolved: the airconditioning regulator was replaced and reprogrammed, as well as a whole bunch of other airco related parts.
Now, when starting, the car can be driving right away (does not stall if you press the gas after 2 secs) as well as the car is MUCH more smooth and responsive. Dealer keeps regulators in stock as they expect other cars to have the same issue.
I have seen posts on a lot of different boards of people who have comparable issues. Go to your dealer and ask them to contact thebimmerstore.com in case they do not fix it / cannot pinpoint the issue.