Yes, I've had it done fairly recently on mine so I can't say too much until I've driven it more. That said there is an improvement, notably in sport. From factory the car would hang on to 2nd gear for all its worth, screaming away to the redline, with the tune it shifts into 3rd sooner.
In standard 'D' the usual lag associated with the gearbox is reduced somewhat.
EDIT - mine wasn't done at the place you mention, I had it done at STA in Buckinghamshire.