I built a leak tester, spent some time with it and a bottle of soap and had no leaks on the intake side. I also had bellowed uppipes, and not a sign of soot anywhere.
I could run the 38R in a 2.8 ms tune (with 100% nozzles) and keep it parked at 1250-1300. Any more then that and we run into the issue where I needed to loosen my gate, which I have accepted. I also run ge@rhead which has less fuel then most under 2k rpms, though I did get two PHP tunes with too strong a mid range pedal for my taste.
My biggest complaint was from the mid to top end. Just felt choked. Ive learned that I could fixed most of that, by loosening the gate, but at this point I would absolutely never go back. Id almost pay double what it cost me to go this route. I doubt a single person with a 38R can post a video of a smoke free 15psi maintained 1,500 rpm ( and keep it under 1200*). And not that it matters, but I was pulling long grades at 24.5k (scale verified) and the temps stayed right where they are, no creeping up. Proof is in the videos.
My goals of going T4 (being that Im a hand shaker trans like you) was to potentially gain top end, without losing spool up (maybe even gain a little there if possible, but I was accepting the same results). And this turbo has not only achieved that, but the spoolup with the 1.0 housing is phenomenal. And a "good spoolup" can be taken so many ways. So thats why I have posted the videos showing where and how well it works.