At least with hardwood, you can see the dust bunnies.
Yeah...I had a love/hate relationship with the hardwood floors at my house. Made it easy to see dirt...which is both good and bad.
I also worried a lot about scratches, though. But I'm positive they're far more sanitary. If you really start to think about carpeting...well, I wouldn't want to really look at one under a microscope, I'm sure.