My dealer says he has increased the boost pressure in an attempt to overcome the hesitation I've been getting around the 3000 RPM mark. This does seem to have improved things, but it's too early to make full comments on this.

What would they have done to increase the boost pressure?

Julian.
MY99 5 door

 

Changing the restrictor is the only thing that I can think of, as the ECU can't be fettled with.