That with respect is a load of Bo**ix , there is no reason there should be a stutter big engine or small . without driving the car its difficult to diagnose but there are other reasons beside ignition components you may have the stutter/ misfire . also the mapping in the standard S is abysmal as it has to cope with temperatures of +40 to - 40 and petrol with octane ratings from 85 to 101 and MINI have just 1 fuel/ ign map . is your problem when pulling away from a junction
or in 'cruise' mode
is it under 'load' conditions ie when accelerating
what mileage is on the car
do you know what spark plugs were used
is the car showing any fault codes
has anyone got any 'live' data to determine the problem
G