Yeah, that chart is awesome!

I've had the same exact fans running on two radiators side by side for many months now. One side is a 480GTX and the other is a TFC480, I can not at all tell a difference between noise on one side or the other when they are turned up the same volts and thats with 4 fans on each, so you'd think it would be obvious.

So at least on my system, fin density doesn't seem to make any noise difference. Sure you'd have to run the fans higher to get an equal CFM level, but this chart is comparing RPM which should make noise pretty much equal at least in the sense of noises that matter (motor/fan chop/vibration).