I use the same types of beepers in your article. They help but the sound doesn't carry as far as you would think once the bird has landed. Also, it helps to beef them up with Kevlar loops and such. I have had a couple of them fall off - deployment is tough on them.
What has helped me more than anything is a handheld GPS in conjunction with the beeper. It works everytime, so long as you can see it come down and get a compass heading on it. I use the GPS to walk a straight line to it. It gets you close enough to hear the beeper anyhow.