Glad eddy beat me to this one since a good portion of my info on balance shafts comes from his writing.

I read your horror stories when building my motor and was going to keep the shafts out of fear but then decided to check the bearings and was left with no choice but a bsek. I feel a bit of a buzz at idle and highway cruising, and a bit of shake just off idle at 1100 ish rpm. Otherwise its fine for a truck. I'm not sure why your motor was that bad.

On SQC almost everyone insists on balancing the motor when eliminating the balance shafts, even Randy. I don't know why.

Off topic, but I worked at an indie German auto shop for a bit... and I have along of doubt in the credibility of some of those engineers. (Especially whoever designed the motors that spec 15w50 in hopes of maintaining engine life. Some people roll in new bearings every 30k just to keep them going). I do see your point though.