the issue is that when you enlarge the port, the plate needs to be enlarged to keep the gaps the same at idle and normal driving. when this step is skipped you end up with too large of a gap between the plate and bore and the car runs like crap. i have seen several customers get burned by this so far. once they get it ported, there is no going back so they end up needing to buy a unmodified throttle body to get the car running correctly again. most companies that port throttle bodies do not bother to make larger throttle plates to match up.