Angry Palm Tree- No, my comments regarding fatigue weren't vibration induced. The only noticable vibes were on my first ride 17 years ago. Decel thru translational then was exciting.
Riding in the 105 is tiring because it IS built like a brick out house. The front pax, who has the "good" seat, is on the floor in the bubble. Think early 60's Sprite with a glass roof and no suspension.
The poor souls in back are nose down, pushing themselves back into the seats at cruise. I remember looking at the horizon thru the greenhouse over the pilots head the whole flight.
Also, the 105 doesn't ride "loose" and pendulous like a Long Ranger. But it never seemed to be in trim for more than a second or two, then it was wandering off in one axis or the other, requiring pilot intervention.