I think the new prop-effect looks absolutely fantastic, if you were at around idle... It should not be as visible at higher RPMs and I purposely try to keep my plane at high RPMs to avoid this effect :p it's annoying as hell when I know what a prop looks like over the cowling of a cessna 172 or piper cherokee warrior. But like I said, effect represents what you see in real life at LOW rpms :p
Like somebody already said, take a model plane if you have one, or take a cooling fan from your PC or just a normal cooling-fan for summerdays and watch the prop go at medium/max RPM. That should clarify some things for the hollywooders. You can only make out this effect if you try to concentrate on the propeller or try to follow the propellers rotation with your eyes, because your eyeball shifts viewdirection so fast you can actually make out the detail of a blade during this small time-window.
Like I previously stated, if we were to do the same realism with a CRT monitor instead of a propeller, we'd get the flickering effect. Try capturing a video with your mobile phone camera, then you'll get an even worse effect of some horizontal lines, because the phone captures the image so slowly. Example:
I probably shouldn't have posted this, we might actually end up with this ingame now as this is new proof of propeller visuals!!!