I can attest to the same. My Axio's ride was no longer soft as soon as I changed parts to the PKDM. Went in search of genuine shocks (exact code) to restore the ride softness. On a regular bumpy road for example, not talking about pot holes, just a regular bumpy road, I could feel the shocks a lot more to the point that would have to reduce speed on the same road...
If you check in KYB shock Catalogue, PKDM parts are usually listed as "ROUGH ROAD PACKAGE". I believe the shaft is thicker on these and the rebound/softness is changed. There's a reason parts are tagged differently by KYB, else one shock for every market would suffice.
P.S. Rear Axio springs do not sit properly on PKDM shocks, one has to change the springs too.