Yep, tubesrule - you have to consider the source and the display and what the eye is doing!
I went through some really dumb arguments with a person involved with the HDTV standards committees who insisted that progressive scan at 72 Hz would _eliminate_ judder on 24 fps film material. Well, it does not, although it is cleaner than the 12 Hz components you get with 3:2 pulldown and 60 Hz displays. I eventually wrote a little program to calculate the relative displacement over time oif the juddered images for any input and display rates.
I always hesitate pointing out the 3:2 judder to people who have not really paid attention to it, because once you notice it, it's hard to ignore.
By the way, film in theaters is shown with a double shutter so that the flicker rate goes up to 48 Hz. Some projectors have used triple shuttering to raise the rate to 72 Hz so the pictures could be brighter without visible flicker, but this usually results in poorer focus, as the film heats and expands between the three presentations of a single frame. Whether with double or triple shuttering, professional film makers are very careful to avoid bad pan rates or rates of motion across the screen, because the judder can look very bad. Micromirror pirojectors for digital cinema can eliminate much of this problem even when the source is only 24 fps, but good cinematographers still are careful.
For some of the tests of HDTV scan formats for the FCC ACATS, we used a ShowScan film, which is shot at 60 frames/second and therefore shows no judder when televised at 60 fps progressive. The ShowScan film is 70 mm, and at their facility they had a floor to ceiling screen that you viewed at about one picture height or less - much more detail than the 1 or 2 megapixel HDTV standards, and therefore an excellent, nearly transparent source material for HDTV tests.