I noticed there were a couple of discussions years back on magnetic knife bars. I thought it worth reposting in order to see if anyone had any specific suggestions and because sometimes products change.
I had a Wusthoff knife bar like the one in the attached photo. (They make 14" and 20" models that I know of). This particular one was made in Germany. And I had it on the wall for a few years. I thought I had it well attached -- though I recently moved it to another area of the kitchen and maybe I wasn't as careful with installation this time -- and wouldn't you know someone using the kitchen while I was away (!) knocked it off the wall and it cracked. These models were securely by two "tabs" that were screwed securely into the wall. And the metal piece "slides" (as it were) onto those tabs. A good design, I think, but if you've got to be precise in installation.
I'm not sure if the Wusthoff magnet strips are relatively expensive or not (about USD50-70), and I don't have a lot of expensive kitchen stuff -- but I use this piece so often (like I do a few of my knives and All Clad and Crueset) that the price for quality (if in fact this is a quality piece compared to others) makes sense to me on stuff like this.
I may just get another Wusthoff but if anyone else has a suggestion, I'd appreciate it.