We both have a GT4088 but Ryan's has the 0.81A/R, mine is the .96
Other differences, mine has 264 cams and pretty good intercooling according to the Motec logs (GReddy 3 row)
The boost doesn't really start to raise rapidly until 4krpm. When it does get going it's a fair bit quicker than the old PHR1 and it doesn't run of of puff before the redline, unlike the the PHR1 which just dies around 6000rpm.
With the .96AR 4088 the spool is coming in later than I thought it would and to keep it in the power band you need to keep it above 4k really. This isn't a problem on a 6sp but but I reckon it'd be no good for an auto.
To be honest, I'm considering swapping down to 0.81AR now. the .96 makes more than enough power for me but I'd prefer it to come on-song about 500rpm earlier really. On the other hand, because it's not on boost all the time it's very economical. I'm getting better MPG than I did from BPU and nearly double what I was getting from the PHR1.
You may well be right. The spool now is certainly nothing to write home about. With the PHR1 it was amazing but that's no use if the turbo is spent by 6k, is it?