It felt like it was lacking power, but difficult to tell after jumping out of the Subaru.
It didn't feel a great deal more powerful then our 1.6 Seat, so after little investigation a common failure was identified with the Diverter Valve.
For the sake of £39+P&P it was worth a look/try. Although a PITA to change as it has to be done from under the car. Also after alot of fiddling about decided to knock up my own long reach allen key by angle grinding the bend off a standard allen key and fitting it in a 5mm socket. Dead easy once this was done.
Result was, YES, it was faulty, Boost is back along with very early spol (almost diesel like) now. So it should be back close to 197BHP with peak torqude from 2,000rpm.