During real, everyday use, that is? I'm looking to upgrade a drive in a MacBook Pro, and am looking at either a 750GB/7200RPM or a 1TH/5400RPM drive. Would I care about the speed difference? Is it worth giving up the additional space on the larger drive?
You will notice the difference. Yet though there are much more features in a disk to care about. (cache, single plate or not, access, seek times, etc) The rpm is only one more factor.
About the noise, power consuming, etc, you can check in storage section of silentpcreview.com. Of course check more details on tomshardware.com , anandtech, etc (those often speak about power usage and noise). Consider the noise in a laptop can be a bit more evident, but often depends on how it's all built. I have seen laptops with 7200rpm disk, not real noise, in my personal perception.
If you really care about speed and aren't tight on money, then get an SSD.
Look for the models that are advertised for use in Macbooks, because they need to fit the space in the laptop and the drive firmware needs to do garbage collection and not rely on TRIM.
The price is something like $200 for 250 GB though.