In a way, it almost feels like eavesdropping to have someone listed as a friend who doesn't list me back. On the other hand, most people have two or three (or more) non-reciprocal links. Mostly I dropped the ones where I felt voyeuristic or sycophantic.
I do get a pang when someone removes me - but that's mostly a tendency to see everything as Meaningful with a capital M, when it's certain for the most part to be nothing personal. If the opposite has been true it's been made abundantly clear, which argues for it otherwise simply being circumstance.
So - the obligatory trimming, the obligatory not-so-much-apologetic-as-explanatory post.