I think I've always liked Benchmarks (even when I didn't know what they were called) for the same reasons that brdad doesn't like them so well. I treasure the idea that an object had some purpose or source that has/had nothing whatever to do with my unexpected stumbling across it. For me it marks a place and a time completely separate from its intended purpose. And then I can research it.
I haven't found even one actual geocache so it remains to be seen whether or not the "numbers" and logging part becomes interesting for me. Meanwhile this is all fun.