It's always struck me how revolutionary (for IBM) the change in architecture from the 700x to the S/360 was. The 709x will probably strike the average reader of today as being arcane, what with sign-magnitude representation, subtractive index registers and so on. The 7080, probably even more so. But then, most of IBM's hardware before S/360 had its quirky side; the only exception I can think of, offhand, would be the 1130, which was introduced at about the same time as the S/360.
The S/360 was a breath of fresh air for IBM. --Chuck Sent from my digital computer
