For all-day office wear, I don't think that I would find any cycling specific shoe that is suitable. Either it is stiff enough for riding, or flexible enough for walking. Too much of a compromise for me.

Are you looking for something to wear all day, or just for a few minutes at the start and end of the day to wear "through" the office? If the latter, I would also give Dromarti a look. I don't have a pair, but I know a couple of people who do, and they say that they are extremely durable, and polish up pretty well. The can make a pass through the office without being noticed.