In my old apartment I had one and loved it. My grandfather thought I was crazy though. "What if an airplane flies over the apartment and shakes then all off the magnet?" he would ask. Of course the magnet is very strong and never did drop anything.
I have two kitchens in my house now, but neither of them have a place for my magnetic holder :( I finally gave in and bought a wooden knife block, but I can't wait for the day I can use the magnet again!
I have them in the restaurant and home. I love them and wouldn't use anything else. Home is important because with all of the small appliances on my counter, a knife block is just in the way, also, you don't have to dry the knives and it's a way to showcase your expensive great looking knives. People always compliment it.