maybe because your new coils for the GU is not compatible with the OME shocks for GQ since GU patrol have different part numbers from GQ. the rear ones have the same but the Hard valve for the GQ is the soft version for the GU. maybe the GU patrol is heavier than the GQ, and they have different spring rates, which is why the hard ride you are experiencing.
ARB::: That's exactly what we thought of, the GU body is definitely heavier than the GQ model. The other GU customer had heavy duty front coils but the front end sagged. While on my front end, the coil for the GU series would simply lift it without any problems. But for chassis parts, it's definitely the same from all aspects.