I've had both on mine and tbh it makes not a lot of difference

As for the tuner i've had no issues and all of the cars i've done have made the numbers(other than mine lol!!)

saff on greens 347bhp
escos on greens 344bhp

and mine was 331bhp with 109k on it on greens

tbh Steve its just ur not holding enough boost imo

Paul