the issue with some of those units is your wastegate a lot of times...
if you want to run lower boost, then you need a big wastegate.. You'll be bypassing a LOT of exhaust fumes around the turbo, and the wastegate needs to be able to flow the gas through it.. If you're running a 35mm wastegate on a huge V8 on 5lb boost, you WILL have boost creep problems...
If you're running a 46mm wastegate on a B16 honda running 30psi, then you're WAY overkill on it.
lower boost = larger wastegate.
the controller doesn't have a ton to do with it- all it does is try to keep the boost where you tell it.. boost creep most usually happens in the situation I stated above, not because of a shitty boost controller.