Anyone have done the VD tip tuning( developed by crazy golf) for their clubs and how's the effect especially on the irons.

I've never tried it maybe T can chime in here.

This is something Crazy has been doing for nearly 3 years however it can only be done with a live session at Crazy where they analyze where vibrations are coming from within your swing\shaft and then install an insert at that point to minimize vibration and unecessary movement.

so what's the effect?

Sounds like the Harrison Shotmaker, which is a DIY install.