Where you based Tim? My ED30 DSG is my daily driver - 50 mile daily commute, fuel economy is improved with map if sensible with right foot. APR do a switchable map that is controlled via the cruise control if you are wanting this kind of flexbility. Revo offer the same control with the select/select plus switch but this has to be plugged into the OBDII port when the car is not running to switch the map. All GTI's have a divert valve, think you are meaning one with a spacer. Personally I don't rate them. This is not to say I don't rate Forge as their products are excellent, I just don't rate DV's with spacers stick the OEM rev D DV
Perhaps you would like a DV that makes a duck call - enjoy