Greg, forget about flywheel figures cause those are only estimations.
Whats important is RWHP figures and to use the SAME Dyno time and time again (if you make changes to the setup and want to measure the difference as TLicense pointed out).
In any case, 380RWHP is extremely impressive from standard injectors let alone hybrid turbos....
Now if you tell me that Rich is pushing 473 RWHP off hybrids on standard injectors....then I will say to that.
At the end of the day, if the plot brings a smile to your face and make you look all butch in front of your mates...then I say that its £40 well spent