My turbos are still running smoothly at 125,000km.
Running 8.5psi for 100,000km, 12.5psi for the other 25,000km.
Never rebuilt, no boost controller. My exhaust change caused the boost to bump up 4psi by itself.
Apparently safe boost level with standard dump pipes is only around ~12.5psi. You can wind it up to ~15psi with the twin pipe modification. Heat is the killer of these turbos, so getting the heat away from them quickly will extend their life considerably.