That's one messed up opinion.
That's like saying that it isn't an overlock unless it has above 1GHz OC.
Also, flickering differs from monitor to monitor. 60Hz on the 957MB isn't a
60hz will pretty much always be bothersome unless the CRT is dark.
75hz might pass on some displays on computer usage, sometimes a bit easier in game usage
85hz will almost always be good unless it's really bright (brighter than most LCDs)
I can look at a white background and see right from there how many hz the CRT has, up to 85hz, at which point the flickering disappears. Until it disappears, it hurts the eyes too much.
I have not seen a single CRT that can achieve flicker free at sub 80hz.