Ah thats right i forgot about that stupid name ford gave that.I think he's referring to the factory 'overboost' function. How there was some magic that you get higher boost levels for a short duration. Fiesta ST's have that as well. Personally I've never noticed, and the 'availability' is so that the option is pretty much always there. Call it 'normal boost' lol.
You should be getting at least 22 pounds, you should run a boost leak testI'll be keeping a close eye to my boost levels with the actual accesport but it seems that I constantly max out at 15-17 psi on every WOT run. With E30 I was expecting more boost, but I understand now that has nothing to do with the boost but rather with ignition, which I HAVE noticed. My RPMs go up fast!
I think TurboGT is on the right track. Didn't even consider where you lived and atmospheric conditions. This is probably the exact reason total boost is lower than someone with same car/tune at sea-level.