yeah, same issue you would have with a vpc when you run more boost than the map sensor can read. (although in my experience the vpc sensor maxed out at 25psi, where the GM reads to 30). But, I do have full tuneability of fuel and timing that the VPC doesn't. I can run the AEM 3.5bar sensor an eliminate my problems, but being the cheapskate DSMer, Ill just make due with the gm3.0 for now.
only thing Im not sure of now is what happens with that aem boost controller when I set it to more than 30psi. Does the alarm go off and shut down the controller? I'm not sure if the alarm can be set higher than the controller's internal map sensor can read until you wire in the external 5bar sensor and set the controller to use it.