I have. I think they are fun, no matter what they turn out to be. I'm a member of a paranormal investigation group, here where I live. One of the ladies that is in the group picked up something that sounds really neat, it could be nothing, but it was fun for us to all listen to it over and over again and try to figure out what was being said. This was picked up at a cemetery investigation that I participated in. While I was there I had an experience that someone else also felt/heard. So to find out weeks later that someone picked something up, not at the same time as my experience but in the general location, was just awesome.
Another experience I had, involved a baby monitor, so once more, could have been nothing. It picked up my step fathers voice, freaked me right out.
I prefer digital.