I had just this the other day after picking the fez up after the 15000 km service. i decided to take it from the dealer for a quick squirt up the highway to see if it responded diff after the
ecu update. i left the lights normally and at about 2000rpm in second gave it some throttle, probly about half and she just died for about a tenth of a second, it seriously was like a flat spot. well i can tell you i was turning to head straight back to the dealer but decided to try it again and it didnt do it and hasnt since, so not quite sure what the go was there but its rather disconcerting to say the least when it happens, kind of like oh crap its going to die.