[niterydr]

It just comes down to packaging. We went with internally gated 50 trims on my stealth and I can get it to 15-16 psi no problem, and it doesn't creep. (heavy duty actuators).
The larger the wastegate, the lower boost you can run because you can bypass enough air.
I still perfer internally gated turbo's for street cars. Routing external wastegates is a pita and really adds to the cost of the build. Not to mention the room they take up. Granted, external wastegates are the way to go, but imho, you need to have a manifold designed for it. Just gafting a wastegate on a 1 exhaust runner is a piss-poor way of managing boost.