Um, ceramic knives in a nutshell...
They're more expensive than steel/carbon knives. However, they're MUCH sharper. You've gotta be really careful with them and have some mad chops. They aren't dishwasher safe. You don't have to steel them with each use like you would a "normal" knife. When they get dull or chip (yes, they chip if you misuse/abuse them--they're ceramic, after all), you have to have them sent in to get resharpened and honed--you can't do it at home (not that I'd recommend that with ANY knife), and most professional sharpening services can't do them. Some companies sell ceramic sharpeners, but...yeah. Don't even get me started on that. The upside is it's usually free to have them serviced. Kyocera makes a good ceramic knife at a fairly reasonable price at all 3 levels (beginner, mid range and professional). Probably what I'd recommend for someone's first set so long as they felt comfortable.
As for Mac knives...they're predominately sushi knives but they make all sorts of traditional ones. They're made in Japan using high carbon steel, chrome and tungsten as well as a couple other metals I can't pronounce, so they're harder and more durable than most blades...they're something like 60 degrees Rockwell in terms of hardness. They aren't dishwasher safe, either. They don't rust or stain that I know of.
In terms of seeing them in action...I know Rob Rainford on License to Grill uses Mac knives. I'm 99% certain that Ming Tsai (Simply Ming, East Meets West) uses ceramic knives, though what brand I dont' know.