It really is somewhat of a personal preference. One thing that has influenced edges is veneered and laminate covered tops. In the case of either you have to leave a sharp edge.
I think a slightly hand broken edge is a thing of beauty. It adds that natural feel to a piece. It does add in lessening the possibility of splintering (in some woods) and will lessen the apperance of dents and dings. It is also crucial for film finishes to help them stand up better, a sharp edge will wear trough almost immediately with use. I pretty much break every edge that will get touched.
If I am in production mode, I put some 220 on a palm sander. The finer grit slows the removal process so I can control just how much to break it. If I am using a hand block then go with 150. I'll usually run one pass at a 45 to the corner to break it, then two more pases to round of the edges of that chamfer. Keep in mind this is hopefully on a very small scale. I also try to be consistent so I get the same feel all over the piece.