OK I went ahead and cut the wastgate pressure hose and here is what I have seen over the past week or so.
1. Prior to doing the mod the boost pressure hardley ever moved past 6 to 10 lbs unless you were at WOT then it hit about 20 max. Now as soon as you begin to put your foot into it the boost guage immediately responds and the pressure builds fast until around 20 lbs. If you go WOT it will hit 28 lbs. You can then feel it de-fuel around 26 lbs. This hasn't thrown any codes yet.
2. You can feel the added power from the extra boost until it begins to de-fuel around 26 lbs. If running down the road and want to pass someone even just lightly pushing on the "gas" will send the turbo straight up to around 20 lbs and it will put you in the seat. If you push too much you will go to 26 and it will defuel.
3. Took a trip from Evansville, IN to Indianapolis, IN yesterday. Ran 65 and 70 all the way there. Averaged 21. 4 MPG over the entire 446 miles round trip. That's up over 2 MPG from the last trip prior to cutting and plugging the hose.
I do see a major downfall and that is if your passing someone and suddenly you need to floor it to get by it will defuel and scare you silly.
Spoke with Quadzilla regarding their boost fooler for the 03 HO and they said that adding their boost fooler will allow the turbo to spool past 28 lbs while telling the computer a lower number preventing the defueling. When installing this fooler on an 03 you must cut and plugh the wastgate hose.
Sorry for the long response.