I was one of those whose belief was to never touch the product balance whatsoever unless there's been a blade replacement or a repair on a blade. At least that's how I've been taught. I've had low vert and lat vibration levels on ground and hover (good enough to go out and take flight measurements) along with slightly high fore/aft vibrations but as I play with HW, PL and tabs it (the fore/aft vib) dissapears. I even edit the adjustments by turning off the product balance and has worked good so far.
It's always interesting to know other more experienced technician's point of view regarding vibration analysis. Specially on 412's.
BTW, we also use RADS.
Cheers
