Ok, I just got off the phone with Imaginauto. They said that the Tial wastegate prevent boost leakage WAY better then the factory wastegate. Due to the internal plastic parts in the factory wastegate giving out faster. Now I think I'm leaning towards the Tial.
EDIT: So it sounds like if you are running a .8 spring you would get actually a little less boost with the factory wastegate. But you would get the FULL .8 BAR with a Tial.....