I am a Technician working on the 412CF model and my current position is in Vibration Analysis where we use the Health Usage Monitoring System (HUMS) which is similar to RADS but ours is hardmounted on the airframe. Another system of adjustment I will periodically use for F/A vibration is inboard tab to the protest of our Field Service rep; I will only use it providing I do not have a lot of ground bounce in the Flat Pitch on Ground regime or if I have to do a radical move of more than 5 degree of tab on a blade set and I prefer less than 3 degree. One thing I never thought of trying though is product balance as we are taught to use it only from the Flat Pitch to Hover regime and only if there is a blade flying out. My all out preferred method is in blade spacing however, I like to have a nice straight track picture with minimal weight and minimal tab input and have some of our fleet flying with the highest vibration of 0.17 ips at 130Kts forward speed.