[Kelvin]

It is a difficult comparison to make. In any earthquake resistant design, you want a measure of ductility - which is not really the same as strength. I think what was been seen in these structures was that the buildings did sway (meaning they achieved their desired ductility), but high stresses occured at rigid joints (because the differential rotations became large). One way to counteract that has been the development of "strong column/weak beam" design. In this approach, a weak point is purposefully placed in the beam near the column. As the building racks and stresses build up, the "weak point" goes plastic and prevents additional damage to the joint.

Engineers have always idealised a structure developing "plastic joints" which would essentially act like a hinge. It may sound dangerous, but the beam still remains connected to the column, only it can rotate considerable amounts without damaging the connection. What engineers couldn't do so well, was predict with certainty where these joints would form. So now, the strong column/weak beam design allows engineers to essentially place a "fuse" in their structures (just like an electrical circuit) so it "blows" when it becomes overloaded.

I can't recall if this point was noted previously in the thread, but probably the single largest drawback to RC construction (from a seismic point of view) is its mass. Force = Mass x Acceleration. The more mass a building has, the more force it develops under seismic ground motion (and hence acceleration). However, they are generally stiffer too, so in the end displacements and rotations are smaller and the level of stress/strain discussed above is not achieved.