Well, I had the worst time with this tail ever but I think I finally figured out the issue.

The tail control was still way sloppy and felt like crap. I tried another 401 gyro mounted in several positions, no change. I tried a new 9253 servo, no change

Linkage was smooth and silky I rechecked it, put on the 93mm carbon blades and rebalanced everything, no change.

Checked the belt and pulleys and the belt tension, reset everything. No change

Put a longer and then a shorter servo arm on the servo, no change.

I thought back to a problem I had with my Eco 8 wagging with ANY gyro and setting, nothing changed it and the tail felt like **** in the air but smooth on the ground, similar problem just a long while back.

AHA!!!! I need to check the Sceadu UNDER LOAD to see how smooth the linkage is, my Eco 8 had a prob with bearings binding against a washer but only under load, it was never detectable on the ground.

I pulled the Sceadu tail assembly off the shaft and pulled on both grips (apart and away from the hub center) and turned them to see if they were smooth in movement under "load". I felt a strange grinding on one of the grips. CRAP! I pulled that grip apart and both of the radial bearings (was using two radial bearings instead of one thrust and one radial) fell apart in my hands, balls were flying and metal parts just crumbled out.

Do ya think that was the issue???

Moral: When in doubt check your parts under load as well, sometimes problems only show up when a 'normal' amount of stress is placed on them.