sorry for late reply....
I've got mk4 golf 1.8T 150bhp, its an earlier 1998 model so i think rather than updating the software on the existing chip, the guy told me they would replace the chip with a new one. They said I'd need to pop around first to ensure my 'ECU code' or something was workable (takes 5mins to check with plug in software), then I'd book it in for about an hour, a bit of soldering later and hey presto....new power.
Course I'll take u for spin Richy! i just need to get an appointment now.
will keep u up to date.